BRUSSELS: Nato warplanes struck on Monday an antenna radar system at Tripoli's main airport which the regime was using to track allied aircraft, the military alliance said.

“The antenna, which was previously used for civilian air traffic control, was being used by pro-Qadhafi forces to track Nato air assets in the airspace over Tripoli and to coordinate their own air defence early warning system,” Nato said.

“This information was provided to the pro-Qadhafi forces with the intent of coordinating their tactical operations against Nato air assets and Libyan civilians,” the 28-nation alliance said in a statement.

The antenna was solely used for military purposes, Nato said.

Nato has conducted air strikes against Moamer Qadhafi's forces for nearly four months as part of a United Nations mandate to protect the civilian population from attacks.