TRIPOLI - The Libyan government called for volunteers to take up arms to fight what it described as "Crusader " forces and rebels, reported the official JANA news agency on Monday.

"The general committee for the defense announces the opening of offices to register combatants, men and women, who want to fight against the Crusader forces and gangs of traitors," added the agency.

NATO has been ratcheting up military pressure on the embattled Libyan leader Muammar Gadhafi to quit.

Libyan officials have continually charged that NATO airstrikes have damaged civilian facilities and killed hundreds of civilians.

The most recent figures from Libya's health ministry show 856 civilians have been killed in NATO air raids since they began in March. The figure could not be independently confirmed.

The world's major powers, the UK, the United States and France, on March 19 started to launch strikes from the air and sea against Gadhafi's forces after the UN Security Council passed a resolution to impose a no-fly zone over Libya and  authorize "all necessary measures" to protect civilians in the North African country.

NATO  formally taken over full command and control of military operations against Libya from the United States on March 31.