Police say three people are dead and two are missing in an explosion aboard a refugee boat that was being escorted by Australia's navy after it was intercepted off the country's northwest coast.

Sgt. Greg Lambert of the Western Australia state police says two people are also missing following the blast. No other details were immediately available about the explosion Thursday.

The vessel had been located Tuesday in the Indian Ocean and was carrying 49 suspected refugees, believed to be from Afghanistan.

Home Affairs Minister Bob Debus said Wednesday that the occupants were being transported to a detention center to conduct security checks and process any refugee claims.