A state funeral has been held for Tunisian opposition leader Mohamed Brahmi who was killed on Thursday by gunmen in the capital, Tunis.
His death has sparked widespread unrest. One protester died in weekend clashes in the southern town of Gafsa.
The interior minister said Mr Brahmi, 58, was killed with the same gun as a fellow left-wing politician, Chokri Belaid, who was shot dead in February.
A Salafist is one of the main suspects involved the murder, officials said.
Gunmen on a motorbike shot Mr Brahmi, who led the nationalist Movement of the People party, in his car on Thursday.
On Saturday thousands of people lined the streets of Tunis as the coffin wrapped in the national flag passed by under military escort.
Mr Brahmi was buried in the same cemetery as another leading opposition figure, Chokri Belaid, who was killed earlier this year.
After the ceremony, anti- and pro-government demonstrators gathered outside parliament buildings in central Tunis. Reports say police used tear gas to disperse them.
Supporters of Mr Brahmi have turned their grief and anger on governing Islamist party Ennahda, with relatives accusing it of complicity in the killing.
The government has rejected the allegations, instead naming a Salafist radical, Boubaker Hakim, as the main suspect.
Hours before the funeral, a policeman was injured when a bomb on a car exploded outside a police station in the capital's La Goulette district.
On Friday thousands of people took part in a protests after the the biggest trade union, UGTT, called a general strike to denounce general "terrorism, violence and murders".
In Gafsa, one demonstrator was killed in clashes with police. The circumstances of his death remain unclear.
Earlier, demonstrators attacked Ennahda's headquarters in Sidi Bouzid, Mr Brahmi's hometown and the birthplace of the Arab Spring revolutions which have swept the Middle East.
Chokri Belaid's murder in February sparked mass protests and forced then-Prime Minister Hamadi Jebali to resign.
Six opposition parties have now withdrawn from the national assembly and called for the Islamist-led government to be replaced by a national unity administration.
Mr Brahmi was a socialist and practising Muslim with a pan-Arab ideology, correspondents say.
He was less prominent than Chokri Belaid and not as critical of Ennahda, which came to power in elections following the January 2011 uprising.
The party has faced growing popular unrest over a faltering economy and a rising radical Islamist movement.
Correspondents say many Tunisians, particularly the young, complain that their quest for secular democracy has been hijacked by intolerant Islamists, including the Muslim Brotherhood which forms part of the current government.