Zawiya, Libya (CNN) -- Rebel fighters in Libya, trying to take over a key western city, faced stiff resistance from Moammar Gadhafi's forces on Wednesday, a rebel commander said.
The fighters hope to seize Zawiya, about 30 miles west of the capital, in an effort to advance on the capital of Tripoli in their fight to topple the Gadhafi regime that has controlled the North African country for decades.
"Most of Zawiya is now in rebel hands, but there are snipers and shelling coming from the east of the city," rebel commander Col. Radwan Fheid said.
"The snipers are near Zawiya hospital. People are leaving. They can't stay because of the shelling. These are the last days, God willing."
Rebels are setting up checkpoints and field hospitals to treat the wounded, many of whom have been shot or struck by shrapnel.
At a hospital in nearby Yefren, doctors said they had treated more than 200 patients over the past four days -- some of them rebel soldiers from any of several front lines, some of them civilians.
Among the latter was a 9-year-old girl who was in her house when it was hit by a missile, sending shrapnel into her, a doctor said. "Unfortunately, there is more than 90% chance that she may lose her right arm here," he said.
Medical staff said they were donating their own blood to keep their patients alive. One man, both legs wrapped in bandages, cried out in pain.
Doctors said there were not enough staff members to properly take care of the patient load.
Zawiya is west of Tripoli on a strategic supply route. Rebel control of Zawiya would represent a major advance toward putting a stranglehold on the Gadhafi-controlled seat of power.
Col. Ahmed Banni, military spokesman for the opposition National Transitional Council, said Tuesday that rebels hope to enter the capital by the end of the month.
The Obama administration has agreed to a NATO request for two additional Predator drones to conduct operations over Libya, a U.S. defense official said Wednesday, a day after the drones began flying. The United States has earmarked up to six drones for the Libya operation in recent months, although until generally only two drones have flown at any one time; some have been armed with missiles.
In Washington, the Libyan Embassy was officially re-opened Wednesday by its ambassador amid a crowd of proud Libyan Americans waving flags and singing Libyan songs.
"This embassy will serve as a symbol of the new Libya here in the U.S.," Ambassador Ali Aujali said outside the Watergate building in Washington where the embassy is located. "We will work tirelessly not only to serve the needs of the Libyans studying, living and traveling in this country, but also to thank the United States government on behalf of the Libyan people everywhere for its continuing support for transition to a free and democratic nation."
The mission now represents the Transitional National Council (TNC), the rebel movement based in Benghazi, that the United States recognized as the rightful government of Libya on July 15.
The embassy was closed in March after the State Department expelled all diplomats loyal to Gadhafi. Aujali, who previously represented the Gadhafi regime in Washington, resigned his post in February, and has since represented the TNC in Washington. He was formally accredited as head of the Libyan mission last week.
On Tuesday, Col. Roland Lavoie, a spokesman for NATO's military operation, said that "anti-Gadhafi forces are now assuming control of the key approaches to Tripoli."
He described the advances as "the most significant anti-Gadhafi territorial gain we have seen in months."
Since the end of July, as the threat from pro-Gadhafi forces has diminished, thousands of people have returned to their homes in the western Nafusa mountains, he said.
Since Friday, the northwest coastal city of Misrata has been free of pro-Gadhafi forces, he said.
And the threat from nearby Zlitan has diminished as pro-Gadhafi forces are being pushed farther west, he added.
Lavoie said rebels had occupied Surman and Sabratha west of Tripoli but added that the regions were "still contested."
However, Libyan state television reported that pro-Gadhafi forces and tribal fighters were "cleansing the city of Sabratha from the gangs of traitors" and had secured the coastal road, a key supply pipeline into Tripoli.
Though the center of Zawiya was under rebel control, "there's still reports of fighting also in the suburbs," Lavoie said.
A spokesman for the Gadhafi government offered a different view on Tuesday.
"We are doing very well," Ibrahim Musa said. "It's true that it's a bit slow; people are still saying that we're not acting immediately and that we're having problems in Surman and Sabratha and whatnot because of armed gangs. That's true, but, God willing, we are able to lead this battle successfully. We will achieve peace and victory."
He added, "We are fighting NATO, not the tens or hundreds of armed gang members. Our war is with the crusaders."
CNN's Barbara Starr contributed to this story.