Beirut, AP—Syrian troops advanced in a major rebel-held town near the Lebanese border amid heavy bombardment from warplanes, artillery and tanks as the country’s bloody conflict marked its third anniversary Saturday, state media and activists said.

The conflict, which began amid Arab Spring protests across the region, started off as protests that turned into an armed insurgency and eventually and full-blown civil war that activists say has killed more than 140,000 people and has seen 2 million people flee the country. Peace talks between the government of President Bashar Assad and Syria’s divided opposition haven’t found a diplomatic solution to the crisis, which has seen sectarian violence rise as Islamic extremists entered the fight.

The main Western-backed opposition group, the Syrian National Coalition, vowed in a statement Saturday marking the conflict’s third anniversary “to bring down the Assad regime that is the main source of the Syrian people’s suffering.” State media in Syria did not mention the anniversary.

On Saturday, Syrian state television said troops advanced in the town of Yabroud, near Syria’s border with Lebanon, and now control of much of the area between the two countries.

The Britain-based Syrian Observatory for Human Rights said the Syrian air force conducted at least 15 air raids on the town as heavy clashes raged on the town’s outskirts. It had no immediate word on casualties, only saying government forces were backed by members of Lebanon’s Hezbollah group.

Yabroud is the last major rebel-held town in the mountainous Qalamoun region, where Assad’s forces have been waging an offensive for months to try to sever rebel supply lines across the porous border.

Hezbollah officials say many of the car bombs that exploded in the group’s strongholds in Lebanon over the past months were made in Yabroud. Hezbollah openly joined Syria’s civil war last year, fighting along Assad’s forces and tipping the battle in its favor in areas close to Lebanon.

Lebanese broadcasters Al-Mayadeen and Hezbollah’s Al-Manar aired live footage from outside Yabroud showing bombs landing over the city. Al-Manar showed footage of dead men, some of them bearded. It also showed Syrian troops shooting and firing rocket-propelled-grenades at rebels in the area.

One of the Syrian commanders in the area told Al-Mayadeen that troops advanced “hundreds of meters (yards) inside Yabroud.” He added that troops captured the nearby Saint Maroun Hill that overlooks Yabroud.

“We will cut supply lines with neighboring countries and the fighters will be besieged in specific areas then wiped out,” the officer, who did not give his name, said. “I advise the terrorists to surrender in Yabroud otherwise they will face death. Surrender before it’s too late. The Syrian Arab army is coming.”

An opposition activist in the area who goes by the name Amer al-Qalamouni denied that troops advanced into Yabroud, saying instead they attacked southeastern parts of the town.

Earlier in the day, the Observatory and Qalamouni said the Yabroud fighting killed a Kuwaiti commander of the Al-Qaeda-linked Al-Nursa Front late Friday.

Al-Qalamouni and the Observatory said al-Kuwaiti was a key mediator for the release of a dozen nuns earlier this week who were held by rebels.