NATO on Tuesday accused the pro-Gaddafi forces of occupying and using civilian facilities for military purposes in Libya, and thus make them valid targets for NATO's airstrike campaign.

Smoke from a burning fuel depot rises over Misrata July 25, 2011. The rebel-held western Libyan city of Misrata is facing chronic fuel shortages as a fire continues to rage through the fuel storage facility at the city's port on Monday, 24 hours after a rocket from pro-Gaddafi forces struck the site. [Xinhua/Reuters Photo]

"(Libyan leader Muammar) Gaddafi forces are increasingly occupying facilities, which once for civilian purposes," said Colonel Roland Lavoie, spokesman for NATO's Libya operation.

These sites include former stables, agricultural facilities, commercial and industrial warehouses, factories, basic food processing plants, added Lavoie.

"By occupying and misusing these facilities, the regime has transformed them into military installations ... rendering them valid and necessary military objectives for NATO," Lavoie said.

In addition, Lavoie said the situations on the ground in Libya remain "very dynamic" as fighting between pro-Gaddafi forces and rebels continue in several fronts.

"In Brega, pro-Gaddafi forces are trying to prevent the advance of anti-Gaddafi forces by using obstacles, including mine fields and burning oil trenches," he said.