Burundi police opened fire on protesters on Tuesday as President Pierre Nkurunziza defied international pressure to end a controversial third term bid, ahead of a regional summit to address the crisis.

One protester died in fresh clashes with police on the streets of Burundi’s capital Bujumbura, while two others were reportedly killed overnight in a grenade explosion.

The latest deaths bring the number of people killed to over 20. This comes at a time when East African leaders prepare to hold an emergency meeting in Tanzania.

Leaders of the East African Community– made up of Kenya, Rwanda, Tanzania, Uganda as well as Burundi are due to meet in Dar es Salaam on Wednesday.

Democratic Republic of CongoPresident Joseph Kabila, South Africa’s Deputy President Cyril Ramaphosa, and the US top diplomat for Africa, Linda Thomas-Greenfield, are also expected to attend.

On Tuesday, police in Bujumbura opened fire on protesters in an apparent attempt to disperse crowds who wanted to attack a police officer’s house.

In another part of the capital, officers fired tear gas at a crowd of about 200 youths.While the police have ripped down barricades on main roads, side streets, key opposition areas remain blocked, guarded by angry mobs.

President Pierre Nkurunziza, a former rebel leader who has been in power since 2005, has come under intense international pressure to withdraw from next month’s election and as well stand down.

Opposition groups insist that it is unconstitutional for Nkurunziza to run for more than two terms.But he argues that his first presidential term did not count as he was elected by parliament, not directly by the people.

"The EAC leaders must tell Nkurunziza to leave power for the good of Burundians,” said Aremus, a 24-year-old protester.

"The summit tomorrow [today] is a test... the heads of state must show their maturity in crisis management by telling Nkurunziza to leave,” said Donatien, another protestor.

The clashes between security forces and demonstrators have raised fears of a return to violence in the central African state, which is still recovering from a brutal 13-year civil war that ended in 2005.

African Union Commission chief Nkosazana Dlamini-Zuma, last week warned that the time was not right for elections, and that it was "clear that there shouldn’t be a third term.”

But Nkurunziza said in a BBC interview that postponing the elections would worsen the situation.

This would cause more voilence,he said.

"Today we are optimistic that the elections will be very peaceful, transparent and also fair. We can assure (you) that we will accept the outcome of the ballot box,”Nkurunziza said.

In Bujumbura’s Musaga District, some 300 women marched singing and chanting slogans against a third term.

"No to the third term for Nkurunziza,” one group shouted.

Over 50,000 Burundians have fled into neighbouring nations since the unrest began, more than half of them to Rwanda.