A number of arrests are being reported in the Sierra Leone capital, Freetown, including the country's interior minister.
Others arrested include some top figures in the former RUF rebel group.
It all appears to be linked to the special court set up to try people with war crimes.
The BBC's correspondent in Freetown, Lansana Fofanah, said he had discovered that Minister of Internal Affairs Sam Hinga Norman had been picked up this afternoon.
Mr Norman was the political leader of the Kamajor militia, allied to the government in its fight with the RUF, during the 10 year civil war.
However, the Kamajor were accused of horrific atrocities during the war - as were the rebels.
Those also arrested include RUF interim leader Issa Sesay
and spokesman Gibril Massaquoi.