According to the Polisario, they penetrated up to 20 kilometres (12 mi) into Moroccan territory beyond the wall before being pushed back or withdrawing towards the "Free Zone" east of the wall.[7] Six Moroccan observation posts or bases were taken by the Polisario,[8] the Moroccan soldiers were surprised, but the attack was finally repulsed and the Polisario suffered heavy losses because of the Moroccan air force.[1] The Moroccan air force sent its Gazelle helicopters.[3]