Mohammed Ghannouchi, Tunisia's interim prime minister, has resigned, as security forces clashed with protesters in Tunis, the capital, who were demanding some of his minsters be removed.
Ghannouchi made the announcement on state television on Sunday, saying that he had thought carefully before taking the decision and that he had the support of his family.
"I am not running away from responsibility ... This is to open the way for a new prime minister," he said. "I am not ready to be the person who takes decisions that would end up causing casualties."
Hours later it was announced that Beji Caid Essebsi, a former minister, would take over the premiership. Essebsi was foreign minister under Habib Bourguiba, Tunisia's president after independence,
Ghannouchi has led the country since Zine El Abidine Ben Ali, Tunisia's former president, fled Tunisia on January 14, following a popular uprising.
But Ghannouchi was a longtime ally of Ben Ali and, though he pledged elections to be held by mid-July, protesters have called for him to step aside.
On Friday tens of thousands of demonstrators took to the streets demanding the prime minster's resignation.
"He's been under real pressure since he took over, really, and that pressure increased in the last 48 hours," Nazanine Moshiri, Al Jazeera's correspondent, reporting from Eastern Tunisia, said.
The North African country saw demonstrations again on Saturday, in which three people were killed, reportedly shot by police, according to sources on the ground.
Security forces fired warning shots and tear gas at the anti-government demonstration, and protesters responded by hurling stones, journalists from the AFP news agency said.
A statement from the interior ministry confirmed that three people had died "from the dozen who were wounded during clashes" .
The statement also said that "several members of the security forces were wounded to different degrees".
An interior ministry official, who declined to be named, told the Reuters news agency that the deaths had occurred after a riot orchestrated by Ben Ali loyalists.
"Those who were arrested have admitted they were pushed by former Ben Ali officials," he said. "Others said they were paid to do it."
The interior ministry statement said more than 100 people were arrested on Saturday and 88 people had been arrested on Friday.
A spokesman for Ennahda, Tunisia's main Islamist group, said Ghannouchi's resignation could pave the way to broader participation in the interim government.
Ennahda was banned for two decades under Ben Ali's rule and had complained of being shut out of the caretaker government run by Ghannouchi.