LUSHAN, China - Wang Xiaochang sprang into action minutes after a deadly earthquake jolted this lush region of Sichuan province last month. Logging on to China’s most popular social-media sites, he posted requests for people to join him in aiding the survivors. By that evening, he had fielded 480 calls.

Never mind that the government had declared the narrow mountain roads to Lushan were open only to authorized rescue vehicles. Two days after the April 20 earthquake, Wang was hitchhiking with 19 gear-laden strangers to the rubble-strewn town. While the military cleared roads and repaired electrical lines, the volunteers carried food, water and tents to ruined villages and comforted survivors of the temblor, which killed nearly 200 people and injured more than 13,000.

“The government is in charge of the big-picture stuff, but we’re doing the work they can’t do,” Wang, 24, a former soldier, said recently, standing outside the group’s tent, which was cluttered with sleeping bags, work gloves and smart phones.

The rapid grass-roots response to the disaster reveals how far China’s nascent civil-society movement has come since 2008, when a magnitude 7.9 earthquake in Wenchuan, not far from Lushan, prompted a wave of volunteerism and philanthropy. That quake, which claimed about 90,000 lives, provoked criticism of the government for its relief efforts. Anger mounted in the months that followed over allegations of corruption and reports that the parents of dead children had been detained after protesting what many saw as a cover-up of shoddy school construction. Thousands ofstudents died in school collapses during the quake.

Like the government, which honed its rescue and relief efforts after the Wenchuan earthquake, the volunteers and civil-society groups that first appeared in 2008 gained valuable skills for working in disaster zones. Their ability to coordinate - and, in some instances, outsmart a government intent on keeping them away - were enhanced by Sina Weibo, the Twitter-like microblog that did not exist in 2008 but now has more than 500 million users.

”Civil society is much more capable today compared to 2008,” said Ran Yunfei, a prominent democracy activist and blogger, who describes Weibo as a revolutionary tool for social change. “It’s far easier now for volunteers to share information on what kind of help is needed.”

One of those transformed by the Wenchuan earthquake was Li Chengpeng, a sports commentator from Sichuan turned civic activist. When the Lushan earthquake hit, Li turned to his 7 million Weibo followers and quickly organized a team of volunteers. They traveled to the disaster zone on motorcycles, by pedicab and on foot so as not to clog roads, soliciting donations via microblog along the way. What he found was a government-directed relief effort sometimes hampered by bureaucracy and geographic isolation.

Two days after the quake, Li’s team delivered 498 tents, 1,250 blankets and 100 tarps - all donated - to Wuxing, where government supplies had yet to arrive. The next day, they hiked to four other villages, handing out water, cooking oil and tents.

The government, however, prefers to rely on statebacked aid groups to deliver supplies and raise money, largely through the Red Cross Society of China. But that organization is still reeling from a corruption scandal in 2011 that damaged its reputation and spurred greater support for nongovernmental charities, which are generally thought to be more transparent.

Faced with a groundswell of social activism it feared could turn into governmentopposition, the Communist Party has sought to turn the Lushan disaster into a rallying cry for political solidarity. “The more difficult the circumstance, the more we should unite under the banner of the party,” the state-run newspaper People’s Daily declared last month, praising the leadership’s response to the earthquake.

Still, the rise in online activism has forced the government to adapt.

Recently, People’s Daily announced that three volunteers had been picked to supervise the Red Cross spending in the earthquake zone and to publish their findings on Weibo.

Yet on the ground, the government is hewing to the old playbook. According to local residents, red propagandabanners began appearing on highway overpasses and on town fences even before water and food arrived. “Disasters have no heart, but people do,” some read. Others proclaimed, “Learn from the heroes who came here to help the ones struck by disaster.”

Analysts say the legions of volunteers and aid workers who descended on Sichuan threatened the government’scarefully constructed narrative about the earthquake. Indeed, some Chinese suspect such fears were at least partly behind official efforts to discourage altruistic citizens from coming to the region.

Despite warnings to stay away, so as not to obstruct roads and become a burden to rescuers, plenty of people found a way into the disaster zone. “I was really surprised athow many volunteers showed up despite the government’s announcement saying they weren’t needed,” said Li Huaping, 47, a well-known political dissident from Shanghai, who was helping to set up 50 tents for use as temporary classrooms.

Information for this article was contributed by Mia Li of The New York Times.

Front Section, Pages 16 on 05/12/2013