Anti-Gaddafi fighters fire a 130mm howitzer at pro-Gaddafi forces near east of Sirte, September 20, 2011.

Anti-Gaddafi fighters fire 130mm howitzers at pro-Gaddafi forces near east of Sirte, September 20, 2011.

Anti-Gaddafi fighters stand outside a village near Sirte, Muammar Gaddafi's hometown and one of his last remaining strongholds September 20, 2011.

Anti-Gaddafi fighters travel towards Sirte to fight Gaddafi loyalists, at the outskirts of Herawa, 55 km east of Sirte September 19, 2011.

Revolutionary fighters celebrate the capture of a tank, draped in sheepskins as camouflage, from pro-Gadhafi resistance forces in Sirte, Libya, Tuesday, Sept. 20, 2011. Revolutionary fighters have not been able to take over central positions in Sirte. Pro-Gadhafi forces have the advantage of knowing the city and are heavily armed, making it impossible for the former rebels to stand in at night after advancing during the day.