Army engineers have used wire mesh fences to block valleys on the border with Yemen suspected of being gateways for infiltrators into the Kingdom, a military source said Wednesday. The difficult terrain at the border has led the military to erect fences to stop the flow of armed infiltrators from Yemen into Saudi territory, especially during night time, the source said. Saudi forces prevented Wednesday a group of armed infiltrators from entering national territory on Mount Dowd and Mount Rumaih, which are now under the full control of Saudi forces. Saudi Apache helicopters bombed the foothills of the two mountains Wednesday to drive away infiltrators relentlessly trying to reach the strategic mountain tops to launch their attacks on Saudi forces. The fighter helicopters were then seen hovering low over the mountain after shooting at their targets.