WASHINGTON (Reuters) - The United States and Britain on Monday called on Burkina Faso's transition authorities to thoroughly investigate the killings of 223 civilians in two northern villages in February that were detailed in a recent Human Rights Watch (HRW) report and hold those responsible to account.

The governments of the U.S. and UK are "gravely concerned by reports of massacres of civilians by Burkinabe military forces in late February," the countries said in a joint statement, calling for the probe.

The HRW investigation alleged the Burkinabe military executed about 223 villagers in February as part of a campaign against civilians accused of collaborating with jihadist militants.

Burkina Faso suspended a number of Western and African media, including BBC Africa and the U.S.-funded Voice of America, over their coverage of the report.

The junta-led West African country's communications council said on Sunday that French television network TV5Monde's broadcasts would be suspended for two weeks, while access to its website would be blocked.

The websites of German broadcaster Deutsche Welle, French newspapers Le Monde and Ouest-France, British newspaper the Guardian, and African agencies APA and Ecofin also have been blocked until further notice, it said.

The U.S. and UK also said they "strongly oppose the suspensions of media outlets."

(Reporting by Katharine Jackson and Ismail Shakil; Editing by Doina Chiacu and Bill Berkrot)