The International Criminal Court has opened a formal investigation into an "endless list" of atrocities committed in the Central African Republic, prosecutor Fatou Bensouda said on Wednesday.

"My office has gathered and scrupulously analyzed relevant information from multiple reliable sources," Bensouda said in a statement.

Around 80 people are missing in Central African Republic after their boat sank last week on the M'poko River south of the capital Bangui, the government said on Wednesday.

A new U.N. mission on Monday officially takes charge of peacekeeping operations in the Central African Republic, tasked with ending ethnic and religious bloodshed and helping to bring political stability.

During a ceremony due to start at the airport of the capital Bangui at 3:00 pm (1400 GMT), the task force known as MINUSCA will pick up the baton from the African MISCA force, backed by French and European troops.

At least 17 people were killed in fighting between rival factions of the former rebel movement Seleka in the Central African Republic, an officer in the African peacekeeping force there said Tuesday.

The dead were all ex-rebels who battled on Monday in the heart of the central town of Bambari, where the Seleka forces set up their headquarters in May, said the officer in the MISCA force deployed by the African Union, asking not to be named.

At least 25 people died when an illegally operated gold mine collapsed for a second time in two years in the Central African Republic, police said Saturday.

"In all, 27 people were buried in the collapse of the gold mine. Twenty-five bodies were found and dug out but two could not be found" after the accident on Thursday near the southern city of Bambari, a police source said.

The Central African Republic unveiled its new government on Friday, a broad coalition including representatives from rival armed groups, after fresh fighting between warring militias killed at least eight.

Prime Minister Mahamat Kamoun, who was appointed earlier this month, has been tasked with bringing rebel groups back into the mainstream to try to end the ethnic and religious violence gripping the country.

Crimes against aid workers have reached a record high in the Central African Republic over the past year, a U.N. official said Thursday after a Red Cross volunteer was killed.

Five people have been killed in fighting this week between armed militants and French peacekeepers in the capital of the Central African Republic, a hospital source said Thursday.

The clashes came after several weeks of calm in the city, where peacekeeping forces have frequently been involved in deadly firefights with rival militias and taken steps to to disarm them.

The new prime minister of the Central African Republic vowed Monday to reconcile a nation torn apart by ethnic and religious violence even as rebels refused to take part in his government.

Mahamat Kamoun, who was named the country's first Muslim premier on Sunday, said his first priority was forming an "inclusive" government, then restoring security and tackling a devastating humanitarian crisis.

The Central African Republic named it first Muslim prime minister on Sunday as part of an effort to create a more inclusive government and end more than a year of sectarian violence.  

Mahamat Kamoun, formerly a special advisor to interim President Catherine Samba-Panza, will lead a transitional government that is seeking to implement a precarious ceasefire signed late last month.