France will send 1,000 troops to Central African Republic to keep growing chaos at bay, the defence minister said Tuesday, announcing his country's second military foray into a troubled former colony this year.

The confirmation from Defence Minister Jean-Yves Le Drian came a day after a top UN official warned of mass atrocities and possible civil war in one of the world's poorest countries, which has been in turmoil since rebel groups joined forces in March and overthrew the president.

The rebels have been accused by rights groups of committing scores of atrocities including killings, rapes and conscription of child soldiers.

"It's in collapse, and we cannot have a country fall apart like that. There is the violence, massacres and humanitarian chaos that follow a collapse," Le Drian told Europe 1 radio. "It will be a short mission to allow calm and stability to return."

Prime Minister Nicolas Tiangaye said Monday French Foreign Minister Laurent Fabius told him France aimed to boost its number of soldiers in the country by 800 from about 400.

France has about 2,800 troops in Mali, an operation that began after rebels and al-Qaeda linked militants moved to take over the capital last winter, but Le Drian dismissed any comparisons between the two missions.

6 months

"In Mali there was an attack of jihadists, terrorists who wanted to transform Mali into a terrorist state. This is a collapse of a country with a potential for religious clashes," he said. "France has international responsibilities."

France will accompany an African force of troops from neighbouring countries, in a mission expected to last about six months, Le Drian said.

In a briefing Monday to the Security Council, UN Deputy Secretary-General Jan Eliasson said that the situation in the Central African Republic was deteriorating so rapidly — with the country becoming "a breeding ground for extremists and armed groups" and never-before-seen sectarian violence between Muslims and Christians — that a UN peacekeeping force may soon be the only option.