Two US soldiers were killed and two injured in a helicopter crash in Morocco during an annual joint military exercise, a US embassy spokesman said Thursday, dpa reported. The incident was being investigated, he said, without giving further details. According to the website of the US Africa Command, the MV-22 Osprey helicopter crashed in an exercise area south-west of Agadir in the south of the country on Wednesday. More than 1,000 US and Moroccan soldiers are staging the African Lion, one of the biggest bilateral military exercises held in Africa.