Syrian rebels battling the regime led by President Bashar al-Assad are running out of ammunition as black market supplies dry up, neighboring countries tighten their borders and international promises of help fail to materialize, according to rebel commanders and defected soldiers who have crossed into this Turkish border town in recent days in a quest for money to buy arms.

They describe what appear to be desperate conditions for the already lightly armed and loosely organized rebel force, made up of defected soldiers and civilians who in recent months have banded together in the name of the Free Syrian Army, transforming what had been an overwhelmingly peaceful uprising into an armed revolt.

The rebels have long been appealing to the outside world for military intervention and weapons to help their struggle. But they are acknowledging for the first time that the rebellion, at least the armed portion of it, might be faltering in the face of a concerted government offensive aimed at definitively crushing the year-old revolt.

“Day after day, the Free Syrian Army keeps fighting and fighting, but day after day, we are running out of ammunition, and, eventually, we just have to leave our area,” said Abu Yazen, 26, a defected soldier who joined the rebels in the summer but fled to Turkey this month with five comrades after they ran out of bullets in the northern province of Idlib.

He is living at one of the civilian refugee camps set up by the Turkish government, among scores of dejected fighters who have been showing up on a daily basis in and around the frontier town of Antakya as their ammunition runs out and hope fades that the international community will come to their rescue.

Since the highly publicized rout of Free Syrian Army fighters from the Baba Amr neighborhood of Homs three weeks ago, rebels also have been on the run within the country, staging retreats across a swath of territory in Idlib and from the eastern city of Deir al-Zour.

The withdrawals were prompted in part by a realization that the effort to hold ground in Baba Amr had been a strategic mistake for the heavily outgunned rebel force, said Capt. Ayham al-Kurdi, a Free Syrian Army spokesman and coordinator living in Antakya.

“In Baba Amr, the fighters put up a good fight,” he said. “But it caused major destruction, and many civilians died. Now we are strategizing to make sure we don’t make the same mistake again.”

Fighters now are withdrawing at the first sign that the government is preparing an offensive, he said, to spare civilians and conserve resources. They plan to focus instead on guerrilla tactics, such as roadside bombings and ambushes.

But even those efforts are facing difficulties as the supply of ammunition dries up. In many parts of Idlib, once envisioned as an internationally protected safe zone for rebels and civilians, fighters have had to suspend operations and go on the run.

As they withdraw deeper into remote mountainous terrain, away from the population centers where they rely on the sympathies of residents for food and support, some rebels are also going hungry.

Among the fighters who have recently turned up in Antakya is Abu Mustafa, 35, a staff sergeant from Idlib who asked not to be identified by his real name or his home town because he fears for the safety of his family.

He made the perilous journey across the mined border after his unit of a few dozen men ran out of ammunition during an attack on a Syrian army checkpoint last week, he said. As the unit retreated toward a mountain hideout, Abu Mustafa said, he collapsed from hunger and had to be helped to safety.

“We hadn’t eaten breakfast, and it was late afternoon,” he said in an interview at one of the many small apartments in Antakya that Syrian activists have rented. “I had no power even to walk.”

The next day, he set out for Turkey, to beg the Free Syrian Army leadership for money.

“I came to tell them we are running out of ammunition and we need fast support,” he said. “Without ammunition, all of us are facing death.”

Black market tightens

A few months ago, as the militarization of the revolt accelerated, it was possible to buy black market supplies from Jordan, Lebanon and, in small quantities, from Turkey, he and other rebel fighters said.

But those governments have since tightened border controls, including reinforcements of troops and police forces to guard possible smuggling routes, strangling the supply of weaponry. Along the Turkish border, new coils of concertina wire glisten in the sunlight, entwined with the rusting barbs of the old fence.

Iraq, where border restrictions are relatively lax, is now the only source of black market weapons, the Syrian fighters say. But most of the arms obtained there come from buried stockpiles left over from the Saddam Hussein era and are of poor quality. Bullets explode in the barrels of guns and rocket-propelled grenades fail to go off, making rebel units reluctant to buy from Iraq.

Syrian authorities also have taken steps to squeeze the rebels’ access to arms, placing land mines along the borders with Turkey, Lebanon and Jordan and acting to thwart what had all along been the rebels’ biggest resource: the Syrian army itself.

Abu Mustafa said his main source of ammunition had been a sympathetic local tank commander in the regular army who secretly funneled boxes of bullets every few days to the rebels. Last month, the tank commander realized that he was under suspicion and fled his unit to join the uprising.

It is still possible to buy ammunition from corrupt members of the Syrian security forces and the irregular pro-government militias known as the shabiha, the rebel fighters say. But prices have soared, with Kalashnikovs costing $2,000 apiece and bullets going for as much as $8 each in some areas, up from $1 to $2 a few months ago.

Money appears to be less of a problem than access to ammunition. Syrian exiles continue to send money to the opposition and to the Free Syrian Army’s de facto leadership, which is housed under close Turkish guard at a special military camp outside Antakya.

“Fighters are coming here expecting the leadership to give them weapons, but we don’t have any. We do our best to help them with money so that they can try to buy weapons inside,” said Col. Malik al-Kurdi, the deputy commander of the Free Syrian Army.

But pledges of financial support, notably from Qatar and Saudi Arabia, have not materialized, and even if they did, the money would be meaningless, given the shortage of supplies, Kurdi said.

Defections continue

The rebels are not giving up hope. They are still present in numerous locations across the country and say they are expanding their activities in some areas that had not witnessed rebel activity, including the province of Aleppo and the northeastern Kurdish region of Qamishli.

Defections from the regular army also appear to be continuing. Free Syrian Army commanders and Turkish media reports say six generals have crossed the border to join the rebels in the past two weeks, although their identities have not been revealed.

The bulk of the rebels’ arsenal is derived from weapons that defected soldiers bring with them, but even that has become a problem. The government recently stopped distributing guns to members of the majority-Sunni rank and file, said Abu Fares, 25, a conscript who showed up at a civilian refugee camp on the Turkish border last week after deserting his unit in Damascus, the capital.

He doesn’t have a gun because his superiors, who belong to Assad’s minority Alawite sect, took away the weapons.

“Of course, I want to join the Free Syrian Army. But they don’t have a weapon for me,” he said. And, anyway, he added, “what use is a gun without bullets?”