KIEV, Ukraine -- Indiscriminate rocket fire slammed into a market, schools, homes and shops Saturday in Ukraine's southeastern city of Mariupol, killing at least 30 people, authorities said.
The Ukrainian president called the blitz a terrorist attack, and NATO and the U.S. demanded that Russia stop supporting the rebels.
Ukrainian officials rushed to defend the strategically important port on the Sea of Azov, beefing up military positions with more equipment and sending in more forces.
The separatists' top leader declared that an offensive against Mariupol had begun -- then later toned down his threats as the scale of the civilian casualties became clear.
President Petro Poroshenko held an emergency meeting of his military officials and cut short a trip to Saudi Arabia to coordinate the government's response. Prime Minister Arseniy Yatsenyuk urged an emergency meeting of the United Nations Security Council. Ukrainian lawmakers are to convene for an emergency session Tuesday.
"The time has come to name their sponsors. The help given to militants, weapons deliveries, equipment and the training of manpower -- is this not aiding terrorism?" Poroshenko said in a recorded statement.
Russia insists that it does not support the rebels, but Western military officials say the sheer number of heavy weapons under rebel control belies that claim.
An Associated Press reporter saw convoys of pristine heavy weapons in rebel territory last week.
The rocket attacks came a day after the rebels rejected a peace deal and announced that they were going on a multiprong offensive against the government in Kiev to vastly increase their territory. The rebel stance has upended European attempts to mediate an end to the fighting in eastern Ukraine, which the U.N. says has killed nearly 5,100 people since April.
The U.N. said Friday that Jan. 13-21 was "the most deadly period" in the conflict since the cease-fire was signed in Minsk, Belarus.
Mariupol, a major city under government control, lies between mainland Russia and the Russia-annexed Crimean Peninsula. Heavy fighting in the region in the fall raised fears that Russian-backed separatist forces would try to capture the city to establish a land link between Russia and Crimea.
Ukraine's Defense Ministry said three separate strikes from Grad multiple-rocket launchers hit Mariupol and its surrounding areas Saturday.
"The area that came under attack was massive," Mariupol Mayor Yuriy Khotlubei said. "The shelling was carried out by militants. This is very clearly Russian aggression that has caused terrible losses for the residents of the eastern part of our city."
The Donetsk regional government loyal to Kiev said at least 30 people -- including a 15-year-old girl and a 5-year-old boy -- died in the attacks. A Ukrainian military checkpoint near the city was also hit and one serviceman was killed, the Defense Ministry said.
The RIA Novosti news agency cited Ukrainian rebel leader Alexander Zakharchenko as saying an offensive had begun on Mariupol. He spoke as he laid a wreath Saturday where at least eight civilians died when a bus stop was shelled Thursday in Donetsk, the largest rebel-held city in eastern Ukraine.
"We began our attack on Mariupol," Zakharchenko said.
He said separatist forces had also begun an attack on a road and railroad hub north of Donetsk and that this attack and the assault on Mariupol were "revenge" for deaths in the war in Donetsk.
In announcing the start of military operations against Mariupol, Zakharchenko did not claim responsibility for the rocket attack.
Zakharchenko swiftly backtracked. He denied that his forces were responsible for Saturday's carnage, saying it was caused by Ukrainian error. He also said the Ukrainian defensive positions around Mariupol would be destroyed but the city itself would not be stormed.
Rebel leaders were quoted on one of their websites saying Kiev's reports of militants shelling were "misinformation and lies."
"The militias did not open fire in the direction of Mariupol, especially the residential areas," the rebels' defense ministry said, according to the website, while Eduard Basurin, deputy commander of the Donetsk rebels, told Russian news service Interfax that government forces had shelled Mariupol in "an act of provocation."
But the Organization for Security and Cooperation's monitoring mission said the attack on Mariupol was by Grad and Uragan rockets fired from areas under rebel control.
Rebel forces have positions 6 miles from Mariupol's eastern outskirts. On Jan. 13, a bus near an army checkpoint north of Mariupol was hit by a shell, killing 13 people. Each side blames the other for that attack.
Yulia, a Mariupol citizen who asked that her name not be used for fear of retaliation, said by telephone Saturday that her stricken neighborhood had no power or heat in the middle of winter because of the attacks. Many residents had boarded up their windows, fearing shattered glass from further attacks, she said.
Mariupol has been under the control of the Ukrainian government, save for a brief period during the early months of fighting when it was under the control of pro-Russian rebels frustrated with the country's pro-Western leadership in Kiev.
Reinforcements were being drafted into the city and the Mariupol-based Azov Battalion was being equipped with more heavy weapons, Interior Minister Arsen Avakov said in a posting on Facebook. Also, security services detained a spotter suspected of giving rebel fighters coordinates to launch rockets, he said.
Some of the civilian deaths in Mariupol may have been because roadblocks were set up too close to residential areas and because of insufficient planning and pre-emptive measures by security officials, Mykola Malomuzh, the head of Ukraine's external intelligence service in 2005-10, said on Hromadske TV.
Yatsenyuk had ordered regional leaders Friday to draw up economic blueprints to put the financially struggling country on a war footing. Ukraine began its fourth wave of mobilization this week, building up manpower for its faltering war effort.
Fighting has also been intensifying for the government-held town of Debaltseve, 31 miles east of Donetsk. The main roads into the town are under separatist control, and rebels have vowed to surround the Ukrainian forces stationed there.
U.S. Secretary of State John Kerry said the rebels' new offensive "has been aided and abetted by Russia's irresponsible and dangerous decision to resupply them in recent weeks with hundreds of new pieces of advanced weaponry."
"I join my European counterparts in condemning in the strongest terms today's horrific assault by Russia-backed separatists on civilian neighborhoods in Mariupol," Kerry said in a statement, citing reports of dozens of people wounded as well.
He urged Russia to close its international border with Ukraine and withdraw all weapons, fighters and financial backing from the separatists or face increased U.S. and international pressure. The European Union and the U.S. have already hit Russia with sanctions for its actions in Ukraine, moves that have hurt the Russian economy.
Ukraine, the U.S. and its allies accuse Russia of supporting the rebels with hardware, cash and thousands of troops, accusations the Kremlin has repeatedly denied. Russia says the government in Kiev is waging war against its own citizens and discriminates against Russian speakers, who make up the majority of the populations of Donetsk and Luhansk.
Russian President Vladimir Putin's spokesman, Dmitry Peskov, declined to comment immediately when reached by mobile phone earlier Saturday.
The European Union urged Russia to use its influence on the rebels to stem the violence. Latvia, which holds the 28-nation bloc's rotating presidency, called for an urgent meeting of foreign ministers.
The escalation "would inevitably lead to a further grave deterioration of relations between the EU and Russia," Federica Mogherini, the EU's chief diplomat, said in a website statement. She urged the Kremlin "to use its considerable influence over separatist leaders and to stop any form of military, political or financial support."
NATO Secretary-General Jens Stoltenberg also condemned the Mariupol shelling and what he called the increased presence of Russian forces in Ukraine.
"Russian troops in eastern Ukraine are supporting these offensive operations with command-and-control systems, air defense systems with advanced surface-to-air missiles, unmanned aerial systems, advanced multiple rocket launcher systems and electronic warfare systems," he said.
A peace deal signed in September in the Belarusian capital of Minsk envisaged a cease-fire and a pullout of heavy weapons from a division line in eastern Ukraine, but that was repeatedly violated by both sides. Foreign ministers from Russia, Ukraine, France and Germany agreed Wednesday to revive that division line, but the rebels Friday rejected the whole Minsk deal.
Senior envoys from Ukraine, Russia and the Organization for Security and Cooperation in Europe issued a statement Saturday convening an urgent meeting this week to restart the Minsk peace process.
Information for this article was contributed by Peter Leonard, Raf Casert and Yuras Karmanau of The Associated Press; by Andrew E. Kramer and Michael R. Gordon of The New York Times; by Kateryna Choursina, Daryna Krasnolutska, Stephen Bierman, Stepan Kravchenko, Sylvia Wier, Aaron Eglitis and Sangwon Yoon of Bloomberg News; and by Karoun Demirjian of The Washington Post.
A Section on 01/25/2015