TUNIS, Tunisia — New political uncertainties gripped Tunisia on Thursday, a day after officials moved to contain the fallout from the assassination of a leading opposition figure. A plan to reshape the Islamist-led administration in favor of a national-unity government encountered strong resistance as protesters again demonstrated on the streets of the capital and elsewhere.

The country’s dominant Ennahda Party rejected the plan to dissolve the government, as proposed Wednesday by Prime Minister Hamadi Jebali.

“The prime minister did not ask the opinion of his party,” Abdelhamid Jelassi, Ennahda’s vice president, said in a statement reported on the party’s website and in Tunisian news reports. “We in Ennahda believe Tunisia needs a political government now. We will continue discussions with others parties about forming a coalition government.”

The statement appeared to inject a new element of political tension into an already fragile situation in Tunisia, the birthplace of the Arab Spring uprisings more than two years ago.

Anxiety about the assassination of the opposition figure, Chokri Belaid, also reverberated to Egypt, where security officials said plainclothesguards had been assigned to guard the homes of prominent opponents of Egypt’s Islamistdominated government. The worries were amplified because of fatwas issued by hardline Egyptian clerics saying that opponents of President Mohammed Morsi should be killed.

Residents of Tunis said hundreds of protesters upset by the assassination - far fewer than Wednesday - took to the streets Thursday, and the French Embassy said on its website it would close its schools in the capital today and Saturday for fear of renewed outbursts of violence.

France is the former colonial power in Tunisia and has traditionally had a strong diplomatic presence in the country.

In the southern mining city of Gafsa, riots broke out and police fired tear gas at demonstrators who threw stones, a local radio station reported. The city is known as a powerful base of support for Belaid.

Some reports also spoke of tear gas being fired in the capital as protesters again converged on the Interior Ministry headquarters in what has been characterized as the worst crisis since the revolt that overthrew Tunisia’s autocratic leader, Zine El Abidine Ben Ali, in January 2011.

Information for this article was contributed by Mayy el Sheikh, David D. Kirkpatrick and Rick Gladstone of The New York Times.

Front Section, Pages 6 on 02/08/2013