Ajdabiya, Libya — Forces loyal to Libyan leader Moammar Gadhafi stormed into this strategic eastern city on Tuesday, deploying artillery, tanks and rockets to pummel rebel positions in a major effort to suppress a rebellion that once appeared poised to end Gadhafi's 41-year-long grip on power.

Hundreds of residents, mostly women and children, fled Ajdabiya with whatever they could carry. By Tuesday night, residents and rebel commanders reported that Gadhafi's forces had withdrawn to the outskirts of the city, a tactic they have used in previous attacks. Still, it increasingly appeared that Libyan forces could soon be within striking distance of Benghazi, the rebels' stronghold.

Libyan state television asserted that Ajdabiya had "been cleansed of mercenaries and terrorists linked to the al-Qaida organization," referring to the rebels.

The assault on Tuesday was the latest sign that the forces that have fueled the Arab spring over the past few weeks are coming under pressure that might prove insurmountable. In Bahrain, the government has declared a state of emergency and invited Saudi troops to quell unrest. In Yemen, police fired bullets and tear gas at protesters on Sunday, a day after security forces killed seven demonstrators in protests across the country.

In Libya, the rebels are up against a military force that is far superior and have been unable to persuade foreign powers to intervene militarily. On Tuesday, recommendations from France and Britain for a no-fly zone over Libya were rebuffed by foreign ministers from the Group of Eight countries.

French Foreign Minister Alain Juppe lamented that Western powers had "missed an opportunity to shift the balance."

"If we had used military force last week to neutralize some runways and the several dozen airplanes at Gadhafi's disposal, maybe the reversal that is happening now to the opposition's disadvantage would not have taken place," Juppe told Europe 1 radio.

The seizure of Ajdabiya by Gadhafi's forces would deliver a severe tactical and psychological blow to the rebel movement and bring Benghazi, 99 miles north of Ajdabiya, within their sights. Ajdabiya sits at the nexus of highways that would allow Gadhafi's forces to either mount a frontal assault on Benghazi or encircle and place a chokehold on it and other pro-rebel cities along the Mediterranean coast.

There were reports that Gadhafi's forces had taken control of the road to Benghazi, cutting off the rebels' primary path of retreat. But Khalid el-Saaya, a spokesman for the rebels' military council, said that the road was still inside "free Libya" and that the rebels controlled it. He also insisted that the government had not taken Ajdabiya.

On the front lines, rebel fighters increasingly accused the movement's leadership of not providing them with adequate military equipment or experienced officers to lead them, despite public promises by senior commanders. On Sunday, Abdul Fattah Younis, the head of the rebel armed forces and Gadhafi's former interior minister, declared that conventional forces, most of them defected soldiers from Gadhafi's army, were playing a significant combat role.

But they were nowhere to be seen Tuesday on what was perhaps the most pivotal battlefront of the rebellion.

"See the scars on my face. Since the morning, I have been fighting on the front. I am tired," said Mohammed Gassar, 31, a former water company employee. "Where is the army? We need heavy weapons, we need leadership."

On Tuesday, Libyan government forces took control of two more rebel-held towns. State television showed pictures of Gadhafi's fighters holding a victory rally in the center of Zuwarah, a small town 76 miles west of Tripoli, and footage of damage caused to vehicles in Brega, west of Benghazi, which had changed hands several times in the past few days.