CAIRO (Reuters) - Egypt s air force killed a large number of militants responsible for a deadly attack on a police convoy 10 days ago, the military said on Tuesday following an air raid on their base. The raid, the second in a week targeting militants behind the Oct. 21 attack, was coordinated with police and based on intelligence about the location of their hideout, a military statement said. Three security sources said at the time that at least 52 police officers and conscripts were killed on Oct. 21 when their patrol came under attack, but the interior ministry refuted that figure the next day and said only 16 policemen had been killed. President Abdel Fattah al-Sisi appointed a new military chief of staff a week after the militants struck and the Interior Ministry dismissed several high-ranking officials. Tuesday s military statement said the air strike was a  continuation of the armed forces and police efforts to avenge the martyrs of national duty . A  large number of terrorist elements  died in the strike, and the air force and police were pursuing several militants on the run, the statement added. Three vehicles loaded with large quantities of weapons, ammunition and explosives were also destroyed in the strike, and the military later posted footage of the attack. An official source in the Giza province security directorate told Reuters more than 12 militants had been killed, though a military spokesman did not confirm any death toll. The military spokesman later said in a statement that a police officer who had been kidnapped during the Oct. 21 attack had been rescued and taken to a military hospital. Egypt has been fighting an Islamic State insurgency concentrated in the northern part of the Sinai peninsula since Sisi led the military overthrow of President Mohamed Mursi of the Muslim Brotherhood in 2013. Hundreds of members of the security forces have been killed since. No group has claimed responsibility for the Oct. 21 attack in a remote desert area of Giza, about 130 km (80 miles) southwest of Cairo. The latest air strike was the second attack on militants in five days - at least 13 militants died in a raid on a farm hideout in the region on Friday.  The vast Western Desert has long been a security headache, with arms flowing across the border with Libya, where militant groups have found shelter since the country fell into chaos after the fall of Muammar Gaddafi in 2011. 