Colombian security forces say they have killed at least 22 rebels of the Revolutionary Armed Forces of Colombia (FARC) near the Ecuadorian border. Police commandos were dropped by helicopter after Air Force planes bombed a rebel camp in the jungle. The fighting in the Putumayo region happened near the town of San Miguel where eight policemen died in a rebel ambush earlier this month. President Juan Manuel Santos said it was the biggest blow in recent times to the left-wing rebel group. He said the operation was a sign of how he would respond to the war strategy of the FARC rebels. Mr Santos said he had given clear orders to the security forces to continue giving these kind of blows without treaty or quarter. President Santos also thanked the government of Ecuador for supporting the operation. FARC have stepped up their violent campaign since president Santos took office on 7 August. More than 40 security personnel have been killed so far this month in a series of rebel attacks and ambushes. Mr Santos has said he will not negotiate with the rebels until they release all their hostages and stop attacks.