The Egyptian public prosecutor ordered that a Libyan militant and 14 others be held for 15 days pending an investigation of their role in a deadly attack on security forces in the western desert last month, state news agency MENA reported on Friday. Charges against Abdel Rahim al-Mesmari will include premeditated murder of police officers, possession of firearms and joining a terrorist organization, MENA reported. The Interior Ministry said on Thursday that Mesmari, from the Libyan city of Derna, was captured by Egyptian forces following the October 20 attack that left 16 policemen dead and 13 injured in the western desert. Security sources initially said at least 52 policemen were killed when militants attacked a patrol, firing rockets and detonating explosives in a remote part of the desert. The Interior Ministry refuted those figures and said 16 were killed. The ministry said previously that it killed 15 militants and arrested 29, including Mesmari, during a raid against the group it blamed for the attack, and said that all had been trained in Dern. Mesmari said Friday that he and other foreign fighters loosely linked to al-Qaeda had been operating out of the western desert since January. In an interview with Mesmari, aired on the private al-Hayat television station, he said he and his fellow militants followed an ideology close to that of al-Qaeda’s and considered the United States their biggest enemy. They also oppose ISIS, he said. "If I fight based on my beliefs, I will hopefully be rewarded," he said, adding that he had first joined a militant group in 2014. "We did not know the police were monitoring us," he said.