FDD rebel leader Pierre Nkurunziza (l) is now minister for good governance

What is the fighting about? Ethnic Tutsis, who make up some 15% of the population, have always held power.

In 1993, a member of the Hutu majority, Melchior Ndadaye, won the first multi-party presidential elections.

But he was assassinated within months and civil war broke out, with some Hutus feeling that the Tutsi-dominated army power would never let a Hutu rule.

Former South African President Nelson Mandela helped broker a peace deal and in May, another Hutu, Domitien Ndayizeye, became president.

But the war still rumbles on and this week shells hit Mr Ndayizeye's official residence. Why is there fighting around the capital?

Because the smaller of the two ethnic Hutu rebel groups remains resolutely opposed to the peace process and has refused to negotiate with the transitional government.

The Forces for National Liberation (FNL) is active in the hills surrounding the capital, Bujumbura, and the army has so far seemed to be unable to stop them launching attacks.

Why doesn't the FNL want to join the government?

The FNL is the smaller, but the oldest of the two rebel groups.

It says it only wants to hold talks with the Tutsi-dominated army, which it believes holds the real power in Burundi.

It does not trust the plans drawn up at peace talks to incorporate Hutus into the army.

But if the main Hutu rebel group does fully participate in the new government and army, then the FNL will start to appear increasingly isolated and vulnerable.

How will the new power-sharing government work and what is its significance?

For the first time in a decade, for the past two weeks there has been peace across most of the country - as the main Hutu rebel group, the Front for the Defence of Democracy (FDD) has stopped fighting.

COALITION GOVERNMENT 4 FDD ministers 40% of army officers 15 MPs Second assembly vice-president Assembly deputy secretary general 2 ambassadors 35% of a new police force 35% of vacant secret service posts FDD fighters to be demobilised

BBC Great Lakes journalist Alley Mugenzi says he feels more optimistic at the prospects for peace than at any time in the past decade.

If it all works out as planned, the FDD will become a key part of a transitional government joining together with the minority Tutsis and moderate Hutus.

Four rebel ministers have been named in the government and are expected to arrive in Bujumbura by the weekend.

FDD fighters are supposed to be disarmed to make up a sizeable percentage of a new army and police force.

It is starting to look like momentum is really building to end the war.

So what will happen next?

President Ndayizeye has had a difficult juggling act to perform since he took charge earlier this year.

He needs to keep hardline Tutsis in the army onboard whilst ceding enough power and influence to persuade Hutu rebels to end their armed struggle for good.

It will require all his skills to keep the FDD on board and get them fully participating in the government and transitional institutions.

Civil wars are notoriously difficult to stop altogether and the FNL has proved impossible to negotiate with so far.

But if it finds itself also pitted against the FDD it may find it soon has little choice but to head to the negotiating table.