CAIRO - More than 20 Egyptian divers are scouring the Nile riverbed in Helwan, south of Cairo, in search of the bodies of two Christian girls who drowned after their boat sank more than a week ago. Seven other girls were killed in the mishap. "Qadri Abou Hussein, the Governor of Helwan, ordered 24 divers to go ahead with the search for Rozifin Refaat and Marihan Welson, who drowned last Thursday," said lawyer Naguib Gabraeil on Thursday. He added that the divers would explore a long stretch of the river in search of the two bodies. Seven other bodies have already been recovered. The Nile passenger boat sank last Thursday, killing nine Christian schoolgirls who had been on a church outing. The boat was on a Nile trip organised by a church in Maadi, and had 19 females on board, more than the boat could handle. Ten girls were rescued, security sources said. The outing was for girls aged between 10 and 18 years old. Meanwhile, Egypt's Chief Prosecutor Abdel Meguid Mahmoud referred the owner of the boat to Court. His trial will start Saturday. "The owner of the ship, Ali Eweis, will stand trial for being the cause of the girls' death, as the boat was found to be unfit for sailing and was carrying extra weight," a legal source said Thursday. Public riverboats in Egypt are often overcrowded and passenger manifests are often absent or inaccurate, but the boat that sank was not a large vessel.