HEESH, Syria » The Islamic fighters peered through rifle scopes and machine-gun sights at the remains of a Syrian military convoy disabled on the highway several hundred yards away. They were peppering President Bashar Assad’s soldiers with gunfire, trying to prevent their escape.

"Here are the heroes and mujahedeen of the Shield of Mohammed, praise be upon him," one fighter said softly as others opened fire.

The Syrian army answered the rebels’ gunfire. Tanks fired into the village from one direction, artillery from another. The ground shook. Smoke and dust rose. Defenseless against the exploding artillery rounds, the rebels kept firing, and were not driven off.

As spring arrives in Syria, the civil war closes out its second year in a mosaic of vicious and widely scattered battles, like this one, where the Damascus-Aleppo highway crosses an open agricultural plain in the south of Idlib province.

Since late last spring, anti-government fighters have wrested much of northern Syria from Assad’s control, overrunning military checkpoints and several bases, and pushing the army back.

But the rebel tide, largely led in northwestern Syria by Islamic groups, moves slowly, checked by weapon shortages and by a lingering archipelago of government positions where the army and loyalist militias have settled in with powerful weapons, equipped for a long fight.

Each of these military positions, and the roads between them, have become minifronts, an almost uncountable set of bloody battlefields where rebels try to silence government outposts, which are mostly arrayed around Syria’s main cities.

It is a bitterly personal war, in which Islamic and more secular fighters share an immediate goal: to protect their own families, an ambition they accuse the West of not adequately supporting.

From its remaining positions, Assad’s army maintains a lethal reach over ground it can no longer walk, firing rockets, mortars and artillery into residential neighborhoods. Often the weakened Syrian air force joins in, dropping bombs. Ballistic missiles occasionally crash in from afar.

These attacks, doled out by the Alawite-led government against a predominantly Sunni Muslim population, and sustained now for many months, are killing civilians, idling the economy and driving families away from their homes. They are also fuel for sectarian anger.

The rebels have had high-profile successes. In January they captured both the Taftanaz air base and Idlib’s main prison. But for months their gains have mostly been incremental.

The battle at Heesh — for one of the few roads in the Idlib region that Assad’s forces still risk using — is, as one fighter described it, a contest for a "death highway" in which one side has a full conventional arsenal and the other is armed with faith as much as weapons. It captures part of the war in a microcosm.

From a knoll rising above farmers’ fields, Heesh overlooks the stretch of four-lane highway between Hama and Aleppo, two cities where the army is thickly garrisoned.

Several Syrian army checkpoints are strung along the asphalt, a bid to keep ground supply lines open — a military imperative for Assad in part because his government’s helicopter fleet has been thinned, making aerial resupply difficult.

Fighting had already ravaged part of the village by last fall, when the government hit it with airstrikes several times. But in late January, hundreds of rebels from an Islamic brigade known as Soqour al-Sham, or the Falcons of Syria, gathered in Heesh and formed a blocking position on the western side of the road.

Another armed group, the Grandsons of the Prophet, took up positions on the opposite side, creating a gauntlet for the army.

The battle has flashed intermittently ever since.

Creeping forward by night and massing by day, rebels now watch from small bunkers, buildings and fighting holes that extend from the town toward the highway’s edge. The army, unwilling to give up a vital leg of road, uses artillery and airstrikes to try to force them back; it has recently struck the town with cluster bombs.

In all, 50 rebels have been wounded and 20 killed in the contest for this tiny place in the past six weeks, according to Fadi Yasin, a spokesman for one of Soqour al-Sham’s battalions.

Blast by blast, what is left of Heesh is being cracked into rubble. Its people have moved away.

The fighters remain, hoping that by cutting off supplies to the army checkpoints north of Heesh they will cause the soldiers there to run low on ammunition, and ultimately to abandon the posts.

Each silenced outpost, they know, is one less outpost that can fire on Idlib’s towns.

Members of the Shield of Mohammad, a fighting unit in Soqour al-Sham, made clear that they intended to drive the army from this road, or die. "I am not talking only about myself, but all of my colleagues here," one fighter, Mohammad Rahmoun, said. "We believe the same thing."

The government has spoken with its own form of bravado.

Early in March, Assad’s state news agency announced that another highway from Hama to Aleppo had been secured and that "this achievement came in continuation of the efforts to eliminate the rest of the terrorists and mercenaries in those areas," according to a statement attributed to the Armed Forces General Command.

The statement added that the newly secured areas were "confirmation of our armed forces’ determination to go ahead with carrying out their sacred national duty in confronting the acts of killing and aggression against our people and homeland."

Yasin, the rebel spokesman, all but scoffed at the government’s claim.

He said that the rebels at Heesh have had their effect; some of the outposts north of the rebels’ blocking positions, he said, have communicated to senior army officers that if their positions are not resupplied then their units will withdraw from them.

Judging from events over the weekend, the army’s operations on the main highway were imperiled. On Saturday, the fighting around Heesh flashed anew after the army tried to send a convoy north from Hama.

The convoy was a mix of cargo trucks, T-72 tanks and fighting vehicles. Four vehicles were hit and stopped, several rebels said, although other vehicles managed to escape and continue on, presumably to the checkpoints slightly farther up the road.

On Sunday, a second army patrol tried to retrieve the damaged vehicles, reigniting the violence.

As the two sides traded fire, and explosions shook the town, the Islamic fighters encouraged one another.

Zahir Darwish, Soqour al-Sham’s military commander, was unmistakably pleased. "Do you know why my men smile like this in such a situation?" he asked.

"Out of my experience in 18 months of constant battles and fighting, I have seen that bravery arrives at a specific point in some fighters, for those who are well connected to God," he said. "They believe in their fates, and that everything comes from God."

Many walked upright at the firing line, startling only slightly when tank rounds slammed against buildings, or artillery rounds screamed in and exploded nearby. On this day, the highway here was cut. The army was stopped. "God is the greatest!" the men shouted, again and again, as the shells landed all around.

© 2013 The New York Times Company