France warns C.Africa crisis could be long

France's defence minister has warned that ending sectarian strife in the Central African Republic could take longer than expected as peacekeepers go door-to-door in the capital Bangui seizing weapons from militia.

A military operation "cannot run like clockwork," Jean-Yves Le Drian said on Saturday after France pledged to send 400 more troops to the war-torn country.

"It has to be adapted, situations have to be taken into account and security needs met depending on events."

French President Francois Hollande said the operation would be brief when it began in early December.

But Le Drian told French radio: "I think it will be longer than planned because the degree of hatred and violence is worse than we imagined."

The European Union and France pledged a sharp increase in the number of troops deployed in the Central African Republic on Friday, as concern mounted over a horrific spiral of violence across the country.

France will eventually have 2000 troops in the country.

German Chancellor Angela Merkel said on Saturday Berlin wanted to bolster its military co-operation with France, particularly in conflict-wracked areas of Africa.

"More convergence is possible", notably in terms of working together in Mali or Central Africa, the chancellor added.

German Defence Minister Ursula von der Leyen has also said she expects to send a medical services Airbus to back up the French mission in the war-wracked Central African Republic.

International troops meanwhile went house to house for about four hours on Saturday in Bangui's Boy Rabe neighbourhood, the base of mostly Christian militias whose attacks have driven many minority Muslims from the city, sparking warnings of "ethnic cleansing".

Automatic weapons, grenades and a large amount of munitions were seized and "more than a dozen" people detained in the unprecedented operation that involved some 250 peacekeepers and police, according to an AFP correspondent on the scene.