BEIRUT: Syrian rebels are battling to seize an army base close to the main north-south highway and say its capture would be a big step toward creating a “safe zone” allowing them to focus on President Bashar Assad’s southern strongholds.

For two weeks they have surrounded and attacked Wadi al-Deif, east of the town of Maarat al-Numan. They say the ferocity of counterattacks by government forces shows how important holding the base is to the president’s military strategy.

If Wadi al-Deif fell to rebels, who already control northern border crossings to Turkey, Assad would be dependent on a single land route – from the Mediterranean port of Lattakia – to supply his forces fighting to win back Aleppo, Syria’s biggest city.

“The battle started 11 days ago. At first we sent small groups to liberate [the base] and we were surprised by the resistance the regime forces showed,” said Lt. Col. Khaled Hmood, a former army officer who defected.

“The regime is fighting fiercely. It seems that it doesn’t care if it loses thousands of troops in order to keep its control over the compound.”

Maarat al-Numan has already fallen to Assad’s opponents, effectively cutting the Aleppo highway. But without control of the nearby military base, their hold over the road is tenuous.

Hmood said he believed around 400 soldiers were defending Wadi al-Deif – a group of barracks barely 500 meters from the Damascus-Aleppo road and backed by air power that Assad has deployed against rebels and Maarat al-Numan residents.

The base may also be an important fuel depot, holding at least 5 million liters of kerosene in five underground bunkers, according to Hmood.

“The regime is bombarding Maarat al-Numan and the villages to pressure us to end the siege,” he said. “By bombarding our families they want to force us to pull back.”

Anti-Assad activists say 40 civilians were killed in airstrikes on the town last Thursday in one of the most intense air offensives of the Syrian conflict.

The army has resorted to supplying Wadi al-Deif by air, dropping bread and other food supplies from helicopters.

But its efforts to send military reinforcements have been repulsed by the besieging rebels. The last attempt on Sunday ended when four tanks were destroyed and the remnants of an army column had to pull back. “We have noticed that the best strategy is to hit its supply line. We have been harming the regime a lot by hitting the reinforcements it is sending.”

Hmood said if rebels could take the base and secure the highway, they could intensify efforts to cut Assad’s second main supply line to the north – the road from Lattakia to Aleppo that passes through the town of Jisr al-Shughour.

“If we liberate these barracks we will be able to protect our backs and move on to Jisr al-Shughour from which we can block supplies and reinforcement coming from Lattakia,” he said. “This will give us a de-facto free zone ... The north will be liberated and will be our enforced free zone, and the battle will be in the south of the country.”

The rebels still face challenges to take the base. Although they have acquired increasingly deadly arms, including artillery and anti-aircraft weapons, they have regularly complained that they have only limited supplies to keep up the fight.