The Central African Republic has declared a state of emergency as armed groups try to lay siege to the capital, Bangui. It will last for 15 days and allow the authorities to detain suspects without the authorisation of prosecutors.
Rebel factions now control most of the country and are calling for the resignation of President Faustin-Archange Touadéra, the winner of December’s election.
Last week the rebels launched attacks on the capital’s suburbs, but withdrew after an intervention by the UN peacekeeping force.
The UN envoy has asked the Security Council for more troops.
The fighting has forced nearly 60,000 people to flee the country.