Armed men attacked a prison in Bahrain on Sunday, freeing several convicts and killing a policeman, the interior ministry said.

"An armed attack on the Jau reform and rehabilitation center resulted in the death of policeman Abdul Salam Saif and the escape of a number of inmates convicted of terrorist crimes," the ministry said in a statement.

Reuters reports that thousands of mainly Shi'ite Muslim Bahrainis are in jail on charges ranging from participating in anti-government protests to armed attacks on security forces in the Western-allied Gulf kingdom, where the US Fifth Fleet is based.