Q&A: Central African Republic's rebellion
Rebels in the Central African Republic have agreed a ceasefire, after taking over several towns, including the key mining centre of Bria, since December.
The unrest has prompted the president to ask neighbouring countries for help - and troops have been sent over the border to help stop the rebel advance.
Who are the rebels?
They are called Seleka which in the local Sango language means alliance.
Seleka is a reference to fighters from three groups - Union of Democratic Forces for Unity (UFDR), the Union of Republican Forces (UFR) and the Convention of Patriots for Justice and Peace (CPJP) - coming together to launch the rebellion.
In 2007, these groups signed an accord with the government and agreed to be integrated into the army.
But in late 2012, some of those rebels who joined the army deserted and took up arms once more.
The rebels, who are mostly northerners, accuse President Francoise Bozize of not honouring the ceasefire deal, which promised the release of political prisoners and payment for fighters who disarmed.
Seleka's main leader is Michel Djotodia of the UFDR. He was a civil servant in the government of Ange-Felix Patasse, overthrown by Mr Bozize in 2003.
Mr Bozize appointed him to a diplomatic post in Sudan, but the two fell out and Mr Djotodia launched a rebellion.
Later, he was exiled in Benin where the authorities arrested him in 2006 under pressure from Mr Bozize's government.
Mr Djotodia was later released and he returned to the CAR.
Another high-profile rebel leader is Eric Neris Massi.
He is the son of Charles Massi, a former government minister who fell out with President Bozize.
Charles Massi has been missing and presumed dead since 2010.
Do they pose a real threat?
They certainly did, until the ceasefire was signed.
Since independence in 1960 the landlocked country has had a history of coups and rebellions, the most infamous led by Jean-Bedel Bokassa who declared himself emperor.
Even the current president is a former army chief-turned-rebel leader, taking power in 2003. He has since won several disputed elections.
As a result of all the instability, illegal weapons proliferate across the CAR, whose forests and rich resources provide cover and money for armed groups.
The government also claims that Seleka's ranks have been swelled by mercenaries from Sudan, Nigeria and Chad. However, the rebels deny this.
The unrest is partly fuelled by ethnic rivalries and poor communities who feel ignored by those in power.
Added to the mix, the Ugandan rebel movement the Lord's Resistance Army has become active in the region - further increasing insecurity.
Can't the army halt the unrest?
It is underfinanced, and its soldiers lack equipment and motivation.
Historically CAR's leaders are wary of having a strong army.
Only the presidential guard, made of troops from Mr Bozize's own ethnic group, has real firepower.
Soldiers from Chad were actually in charge of the president's personal security until October 2012 when they were withdrawn.
Why is Chad so involved in CAR?
Mr Bozize came to power with the assistance of the Chadian army.
Chad's President Idriss Deby wants a close ally to the south.
The unrest in CAR represents a serious security threat to Chad.
The countries share a long and porous border and Chad already hosts several thousand refugees who have fled fighting over the years.
In the past, Chad has faced rebel attacks from groups based in Sudan, its neighbour to the east.
It does not want another area where rebel groups could base themselves.
And it has intervened on several other occasions since 2003 to put down rebellions.
Its most recent foray into CAR was to help defeat a rebel group whose leader, Baba Ladde, was from Chad.
Is the international community doing anything to help?
There are two international peace missions in CAR:
- The UN Integrated Peace Building Office in Central African Republic (Binuca), whose staff has been trying to encourage dialogue between disparate groups
- And a European Union-funded regional force, known as Fomac or Micopax, which has a mandate to protect civilians and is involved disarmament exercises.
France has always maintained a military presence in its former colony - and currently has between 200 and 250 soldiers based at Bangui airport providing technical support to the Fomac mission.
CAR's neighbours - Gabon, Cameroon and Congo-Brazzaville - have pledged to bolster the 400-strong Fomac force, saying they are sending an extra 360 troops to protect the capital, Bangui.
South Africa is also sending 400 troops to help safeguard the capital.
The Ugandan army, helped by US military advisers, is also trying to track down the LRA fighters in CAR.
What is in the deal?
Apart from the ceasefire, a government of national unity will be formed.
This will be led by a prime minister from the opposition but President Bozize retains his position until the end of his term in 2016 - the rebels had said they wanted him to go.
The new government will be tasked with restoring peace, organising legislative elections and reforming the security forces.