The Syrian rebels' defeat in Qusair cost them more than a strategic stronghold. It has left them with a battered spirit and deep frustration.

Their lesson from the fight: No matter how hard they try, they run into a major wall — their weapons are no match for the regime's. Desperate for successes, some in the opposition are calling for changes in tactics, away from trying to hold untenable territory toward more radical operations, such as attacks on military bases to seize weapons or even increased suicide bombings against regime strongholds.

The loss of Qusair, a town near the Lebanese border, was particularly stinging. Over the course of a year, rebels holding the town had heavily fortified it with tunnels, mine fields, and booby traps. When the regime assault came last month, with Syrian troops backed by elite Lebanese Hezbollah guerrillas, they fought back ferociously.

But in the end they were outgunned and outnumbered, and were forced into a harrowing flight when the town fell last Wednesday.

Only now emerging from hiding after their escape, several activists and a doctor who had been in the town described fleeing with thousands of residents and fighters, with the wounded hobbling on crutches or being carried for miles across the countryside. They came under repeated attack in the fields as regime forces chased them from village to village in a four-day pursuit, killing more than 100 rebels and civilians, they told The Associated Press.

"We can't feel our feet after the long march," said Hadi Abdullah, an activist who had been in Qusair coordinating with the rebels. In the group he fled with, there were 800 people who had been wounded during the three-week siege of the town. The first fled in vehicles, but then had to abandon them to go off road, trying to escape attention. "We walked for a long distance on foot. We had doctors and nurses but no supplies."

"For sure, the regime outdid us in this battle, but this doesn't mean we will surrender," he said.

Building on its triumph in Qusair, a key crossroads town of supply lines between Damascus and western and northern Syria, President Bashar Assad's military is now pressing ahead with an offensive against rebel-held areas in two major cities further north, Homs and Aleppo.

Prompted by the regime's advances, the Obama administration began discussing Monday whether to arm Syria's rebels. U.S. officials said a decision could come later this week. The U.S. and its European allies have been reluctant to provide more sophisticated weapons, fearing they would fall into the hands of extremists among rebel ranks.

For the rebels, Qusair's loss marks a new phase in the grinding civil war, now in its third year with more than 90,000 killed. Now, they face a more confident Syrian military, backed by Shiite fighters from Iraq and Lebanon's Hezbollah.

After the fall of Qusair, for example, rebel advances in Eastern Ghouta, a suburb southeast of Damascus, came to a halt, said the spokesman for the rebels' Military Council of the Damascus Suburbs, who identified himself by his first name, Mosab, for security reasons.

"It had a morale impact definitely. Some battalions were distraught, but others rose up to avenge Qusair," he said. "Of course the regime is on the offensive, aided by outside forces ... The only way for us to tip the balance is to be steadfast."

Speaking Monday by Skype, he said the rebels will always be at a disadvantage compared to Assad's forces, so they must shift tactics. Rather than trying to hold more vulnerable areas while hoping for the international community to provide weapons, he said fighters should focus more on hitting large military bases to seize arms. "That would tip the balance."

An activist in Homs who coordinates with fighters in its old city called for a greater use of suicide bombings in regime strongholds. He pointed to a suicide bomber who detonated his vehicle three days after the fall of Qusair in a Homs neighborhood inhabited largely by supporters of Assad from his Alawite sect. Seven civilians were killed.

"We should take the battles to the heart of Alawite neighborhoods," said the activist, who spoke on condition he be identified by his nom de guerre, Abu Bilal al-Homsi, for fear of retaliation.

On Tuesday, two suicide bombers set off blasts in a central square of Damascus, the first in Assad's seat of power since Qusair's fall, killing at least 14 people.

The Islamic militant Jabhat al-Nusra, made up largely of foreign jihadis fighting alongside the rebels, has carried out suicide attacks in the past, and it was not clear if Tuesday's blasts mark a new trend. The mainstream rebel leadership has so far shunned the tactic, fearing it would turn world opinion against them.

But the rebel camp is profoundly fragmented, and more could be drawn to suicide operations if Assad's forces continue their momentum.

"I warn that if the international community continues to fail us, the area will be on fire. If Jabhat el-Nusra and al-Qaida offer us help we will take it," warned Abdullah, the Qusair activist.

For the rebels, losing Qusair was particularly painful because fighters controlling the town — around 3,000 at their height, according to locals, including foreign fighters — had prepared for more than a year in anticipation for a regime attack, with trenches, tunnels and boobytraps. Dozens of Hezbollah fighters were killed in the fierce resistance to the siege.

"They booby-trapped everything," from doors to refrigerators, said Hisham Jaber, a retired Lebanese army general who closely follows Syria's war and heads the Middle East Center for Studies and Political Research in Beirut. "They would lure Hezbollah fighters to mine fields."

But regime firepower was eventually overwhelming. The attackers adopted a new technique of leveling "row after row of buildings" to deny rebels cover and advance into the town, said Rifaei Tammas, a Qusair activist whose brother was among the fighters.

By the 17th day of fighting — the day the regime finally captured the town — the rebels' numbers were down to the hundreds, he said. Tammas described frenzied discussions between rebels on what to do next as the regime opened multiple fronts. They decided to move north, the only crack in the siege, he said.

Emerging this week in the Lebanese border town of Arsal after days on the run, Tammas wrote on his Twitter account that his brother was killed in the chase and shelling hit civilians as they fled on the road out. "I still cannot believe I survived honestly," he wrote.

Jaber, the analyst, said the regime forces left the north open to more easily take on the rebels as they fled through open fields.

Abdullah said he fled in a group of several thousand fighters and civilians, including 800 wounded, some carried on stretchers. They first took refuge in the nearby village of Dabaa, then fled again after that came under attack, walking for miles to fields around other nearby villages, while being bombarded.

"Some people ate tree leaves," he said. "Some young ones found a potato field and ate them raw." He said he documented 110 from his group who were killed, including 40 women and children and 20 rebel fighters.

Kasem Alzein, a doctor who escaped with Abdullah and is now in Lebanon, told AP that their fleeing group came under assault in the fields by tanks and artillery, sending people scattering, some dropping the wounded, while rebels with them fought back.

Along the way, he made a pleading video, pointing to bloodied wounded lying under trees.

"This guy will die only because we have nothing for him," the gray-haired doctor said, choking on tears. "It is a simple injury that would require a simple surgery."