Tunisia's ruling Islamists Thursday rejected plans by the prime minister to form a government of technocrats while the main trade union called a general strike amid renewed unrest, deepening a crisis sparked by the killing of an opposition leader.

With tensions running high since the murder Wednesday of a leftist opposition leader, Chokri Belaid, clashes between police and protesters broke out in the capital and in a central town, AFP correspondents said.

A senior member of Tunisia's ruling Islamist party on Thursday criticized the decision by Prime Minister Hamadi Jebali to form a government of technocrats, reflecting the divisions within Ennahda.

"As far as we are concerned, our country still needs a government coalition based on the results of the elections on October 23, 2011" that Ennahda won, said Abdelhamid Jelassi, a member of the party's political bureau.

Tunisia was hit by strikes Thursday as the murder of an outspoken opposition leader threatened to reignite violence despite the premier's attempts to defuse the crisis by pledging to form a new government.

Lawyers and judges across the country as well as teachers at Mandouba university, near Tunis, kicked off a two-day strike in response to the killing of Chokri Belaid outside his home on Wednesday, officials said.

Tunisian Prime Minister Hamadi Jebali said Wednesday he would form a government of technocrats without political affiliations, after the murder of opposition leader Chokri Belaid sparked violent protests.

"I have decided to form a government of competent nationals without political affiliation, which will have a mandate limited to managing the affairs of the country until elections are held in the shortest possible time," Jebali said in a televised address to the nation.

The United States on Wednesday denounced the killing of prominent Tunisian opposition figure Chokri Belaid, describing it as an "outrageous and cowardly act."

"The United States strongly condemns this morning's assassination of Chokri Belaid, a Tunisian political party leader and a prominent opposition figure under the (Zine El Abidine) Ben Ali regime," the embassy in Tunis said.

Four Tunisian opposition groups, including the Popular Front of slain opposition leader Chokri Belaid, announced on Wednesday they were pulling out of the national assembly and called for a general strike.

The decision was taken at a meeting after Belaid was gunned down as he was leaving his home earlier on Wednesday, in an act that his family and supporters have blamed on the ruling Islamist party Ennahda.

Tunisia President Moncef Marzouki denounced "the odious assassination" of his friend and opposition leader Chokri Belaid in an impassioned speech Wednesday that brought tears to the eyes of Europe's politicians.

Speaking before the European Parliament in Strasbourg, a city where he spent many years in exile himself, Marzouki said hours after Belaid was shot dead that his murder would not tip Tunisia to unrest.

The head of Tunisia's ruling Islamist party Rached Ghannouchi on Wednesday denounced the murder of a secular opposition leader, saying the killers wanted a "bloodbath" in Tunisia.

"They want a bloodbath but they won't succeed" in creating one, Ghannouchi, whose party has been blamed for the murder, told Agence France Presse.

The Seychelles said on Wednesday the son-in-law of Tunisia's deposed dictator Zine El Abidine Ben Ali has requested asylum in the Indian Ocean archipelago.

"The Seychelles government wishes to confirm receipt of a request for asylum that was submitted to the Ministry of Home Affairs by a Tunisian national, Mr. Sakhr El Materi, who is currently in country," the foreign ministry said in a statement.

Prominent Tunisian opposition leader Chokri Belaid was shot dead on Wednesday, sparking deadly protests, attacks on offices of the ruling Islamist Ennahda party, and the pledge of a new government of technocrats.

Furious protesters built barricades in central Tunis and clashed with police, and four opposition groups including Belaid's Popular Front bloc said they were pulling out of the national assembly.