BEIRUT — Syrian troops captured a contested suburb of Damascus Wednesday as the government forged ahead with a punishing military offensive that already has taken four other opposition strongholds south of the capital, state media said.

For more than a year, much of the belt of neighborhoods and towns just south of Damascus has been a rebel bastion and a key arms conduit for the opposition.

But government forces — bolstered by fighters from Lebanon's Shiite militant Hezbollah group and Shiite militants from Iraq — have made significant headway in recent weeks in the area as President Bashar Assad pushes to shore up his hold on the capital and its doorstep.

The town of Hejeira on Wednesday became the latest rebel-held suburb to fall into government hands. The SANA state news agency said the army seized control of the town, but was still battling rebels on the outskirts.

The Britain-based Syrian Observatory for Human Rights activist group confirmed that government forces were in control of most of Hejeira, but said there were still small pockets of resistance.

Lebanon's Al-Mayadeen TV, which had a reporter embedded with Syrian government forces in the offensive, broadcast what it said were live images from the streets of Hejeira, showing shattered store fronts, sandbags piled at street corners and the gutted concrete hulks of apartment buildings.

The opposition's hold on Hejeira became untenable after the military captured the adjacent town of Sabina in recent days.

While the government has driven the rebels from several of their footholds around the capital, the opposition is still within striking distance of the center of Damascus, and fires barrages of mortar rounds into the city daily.

On Wednesday, mortar shells slammed into the Bab Touma and Zablatani neighborhoods of Damascus, killing at least two people and wounding some 20 others, according to SANA. The Observatory put the death toll at three.

In addition to its advances on the periphery of Damascus, the government also has made inroads in recent weeks outside the northern city of Aleppo. Assad's forces have wrested back a military base near the city's international airport as well as two towns along the highway southeast of the air field.

Observatory director Rami Abdurrahman said government helicopters on Wednesday were dropping barrel bombs on rebel positions inside Tel Hasel, which is the sole town along the highway still in opposition hands.

Aleppo has been a major battlefield in Syria's 2 1/2-year-old conflict since last summer when rebels launched an offensive on the city. More than a year later, Aleppo is now carved up into rebel- and government-held areas, and fighting has left much of the city in ruins.

While the battle for the city has been stalemated for months, the rebels are clearly concerned about the government's latest push. A group of six prominent rebel brigades has called for all fighters in the city to come together to repel the military offensive, activists say.

The armed opposition in Aleppo and the surrounding countryside has been crippled by recent infighting, which has undermined the rebels in their efforts to oust Assad.