At least four people have been killed in fresh protests in Burundi, witnesses say, after President Pierre Nkurunziza vowed not to seek a fourth term.
A government supporter was burnt alive and an opposition supporter was shot in the head, the witnesses said.
The African Union (AU) has joined the US in urging Mr Nkurunziza to drop his plans to seek a third term at elections due in June.
The unrest is the worst in Burundi since a civil war ended in 2005.
Seventeen people have now been killed in almost daily protests since Mr Nkurunziza announced late last month that he would seek to extend his 10-year rule.
The government has denounced the protesters as "terrorists" who were leading an "insurrectional movement".
Witnesses told the BBC that in the latest violence three opposition supporters were killed - two were shot by police while the third was killed in a grenade attack blamed on supporters of the ruling CNDD-FDD party.
A member of the party's youth wing, Imbonerakure, also died after being set on fire by protesters in what appeared to be a revenge attack, the witnesses added.
The violence took place in the capital, Bujumbura, and in Gisozi, a rural area about 50km (30 miles) away.
This is the furthest that the protests have spread, correspondents say.
AU commission chief Nkosazana Dlamini-Zuma said elections could not be held in Burundi in the current climate.
"Other than the Burundi court, all interpretation that we get about the constitution is that... really there shouldn't be a third term," she told Chinese broadcaster CCTV.
In a televised address on Wednesday, Mr Nkurunziza called for an end to protests so that the election could go ahead peacefully.
He vowed it would be his last term and said all those arrested would be released if the protests stopped immediately.
Foreign ministers from four Eastern African states are in Burundi in an attempt to end the crisis.
Last week, the US accused Mr Nkurunziza, a former rebel leader, of violating the 2005 peace accord by seeking re-election.
Burundi's constitutional court ruled on Monday that Mr Nkurunziza can run for a third term.
The ruling came after the court's vice-president, Sylvere Nimpagaritse, had fled Burundi, saying the court had been under pressure to endorse Mr Nkurunziza's re-election bid.
The president's spokesman Gervais Abayeho denied that judges had been threatened or pressured.
Under the constitution, presidents can only be elected to two terms in office but it was argued that his first term does not count as he was appointed by parliament.
The UN refugee agency says that more than 20,000 people have left for neighbouring countries because they fear violence could escalate in Burundi.