LONDON (AP) — A British judge was shown graphic pictures of dead and mutilated Iraqis who allegedly died at British hands as a public inquiry began Monday into claims that U.K. soldiers murdered and abused civilian detainees after a 2004 battle in southern Iraq.

The Al-Sweady Inquiry is investigating claims that up to 20 Iraqis were tortured and killed in May 2004 at a British military base in Iraq’s Maysan province after a battle between British troops and insurgents. It is looking at some of the most serious allegations made against British forces during the war in Iraq and is named after one of the dead, 19-year-old Hamid Al-Sweady.