Tunisia's Salem Labyedh resigns after Brahmi's murder
Tunisia's Education Minister Salem Labyedh has resigned following last week's assassination of opposition MP Mohamed Brahmi, the prime minister's office has said.
The secular politician's decision came amid growing pressure from opposition groups on the Islamist-led government to step down.
He is the first minister to quit the fractious coalition since the killing.
The government blamed Salafist hardliners for Mr Brahmi's murder.
Tunisia is the birthplace of the Arab Spring, but it has been in turmoil since the overthrow of long-serving ruler President Zine al-Abidine Ben Ali in 2011.
The BBC's Sihem Hassaini in Tunis says the resignation of Mr Labyedh is a major blow to the government, led by the Islamist Ennahda party.
Mr Labyedh, an independent, joined the government in March following the assassination of another leftwing politician Chokri Belaid.
It would not be surprising if more ministers quit, as the government comes under pressure to create a new unity government, our reporter in Tunis adds.
On Tuesday, Interior Minister Lotfi Ben Jeddou raised the possibility of resigning following the killing of at least eight soldiers by suspected al-Qaeda-linked militants near the Algerian border.
A junior secular party in the coalition, Ettakatol, has also warned it will withdraw from the Constituent Assembly (CA) if a new unity government is not formed.
The CA is weeks away from drafting a new constitution that will be put to a referendum.
On Tuesday, Prime Minister Ali Larayedh said the government would fulfil its mandate and hold elections in December.
A roadside bomb exploded on Wednesday south of Tunis as a police patrol passed, but no injuries or damage were reported, Reuters news agency reports.
"We are facing two choices. Either we confront terrorism together, or we will distract the army and security forces with political battles that are much less dangerous than terrorism," said Noureddine Bhiri, the prime minister's spokesman.