SIRTE, Libya -- Revolutionary fighters on Friday assaulted a convention center in the heart of Sirte that forces loyal to Muammar Qaddafi turned into their main base, in what commanders said was a final offensive to crush resistance in the holdout city after weeks of siege.
The forces of Libya's new rulers were pushing into the Mediterranean coastal city from the west, east and south in heavy fighting, trying to squeeze Qaddafi loyalists into a smaller and smaller perimeter. The two sides battered each other with rockets, mortar shells and tank fire, as
Qaddafi snipers fired down on fighters advancing through housing complexes. Friday's push marks the largest new assault on the city for weeks.
Smoke drifted over the skyline and explosions thundered throughout the city, as long lines of residents fleeing by car formed at revolutionary forces' checkpoints.
Fighters entering through the western gate quickly advanced to within just a mile of the city center but faced heavy resistance from a loyalist force of roughly 800 men, according to one commander's estimate.
"We started the attack at 6 a.m. today. The first group hit the outskirts of Sirte. We were fired on by Qaddafi snipers. We had many soldiers wounded," said commander Altaib Aleroebi of the ex-rebels' West Mountain Brigade, which led the attack on the western front.
At least 12 revolutionary fighters were killed and 195 were wounded, doctors said. Ambulances sped down Sirte's main avenue to a field hospital set up in an abandoned villa five miles from the center. Doctors said a senior commander, Ali Saeh of the Free Libya Brigade, was injured, shot twice by a sniper as he led fighters through loyalist forces in a residential area.
"We are receiving many gunshot wounds, mostly to the head, neck and chest from sniper fire. We have received many injured today," Dr. Ahmed Mohammed Tantoun said Friday, adding he expects many more injured fighters to arrive through the day as fighting intensifies.
Sirte, Qaddafi's home city, is considered the most crucial of the areas that remain in the hands of supporters of the former Libyan leader, more than a month after revolutionaries swept into Tripoli and ousted him from power.
Leaders of the interim government have said that once Sirte falls they can start a timetable for elections. Sirte is key to the physical unity of the country, since it lies roughly in the center of the coastal plain where the majority of Libya's 6.5 million people live, blocking the easiest routes between east and west. Qaddafi loyalists, however, still control another major city, Bani Walid, in the central mountains, and Sabha deep in the deserts of the south.
Revolutionary fighters have been besieging Sirte for three weeks, facing grueling resistance as they inched their way in, let residents flee and simultaneously moved to encircle the city before the final assault. Qaddafi's loyalists have been barricaded in the Ouagadougou Center, a grandiose conference hall that Qaddafi built in the city to host international summits. From there they have been able to dominate the defense of surrounding residential areas.
As the attack continued, civilians fled the besieged city, which is suffering shortages of food and other essentials. Former rebel fighters checked the contents of their bags and cars.
"We had to go today ... there is nothing left, no food, no gasoline," said Sirte resident Ahmed Mohammed.
U.N. envoy Ian Martin appealed to both sides to respect human rights and look ahead to national reconciliation.
He urged the forces of Libya's new leaders not to take revenge on those accused of war crimes, saying they should be detained and brought to justice.
"This will lay the foundation for national reconciliation and the future unity of the people of Libya," he said.
Deputy defense minister in the transitional government, Fawzi Bukatif, told The Associated Press on Friday that revolutionary forces were poised to enter the city from all fronts in what he called a final attack on Sirte.
Revolutionary fighters launched an assault on the convention center in the morning Friday, said Aleroebi, who commanded fighters who led the attack. Backed by rocket and tank fire, they pushed into the city, facing heavy machine gun and sniper fire, he said. The fighters drove loyalists back from a wall near the Ouagadougou Center, he said.
Fighting was also going on around a Qaddafi palace complex and Green Square, the public plaza at the center of Sirte, between the convention center and the sea, commanders said.