Al Qaeda's affiliate in Syria killed at least 20 Druze villagers in the country's north and Western-backed rebels entered a predominantly Druze enclave in the south, activists said Thursday, in incidents that could pull the minority sect into the forefront of the country's four-year civil war.

The killings in the northwestern province of Idlib are the deadliest against the Druze sect, which has been split between supporters and opponents of President Bashar Assad since Syria's crisis began in March 2011.

The Druze villagers were killed Wednesday in Qalb Lawzeh village in the Jabal al-Summaq region, where Nusra Front fighters have dug up historic graves and destroyed shrines in recent months. The militants have also forced hundreds of members of the sect, whom they consider to be heretics, to covert to Sunni Islam.

The Britain-based Syrian Observatory for Human Rights said the Qalb Lawzeh shooting occurred after the Nusra Front tried to confiscate the home of a Druze government official in the village. It said the militants shot one villager dead, prompting another to grab one of the Nusra Front men's rifles and kill a member of the Al Qaeda affiliate. The Observatory said the militants later brought reinforcements and opened fire, killing 20 villagers.

The main Western-backed Syrian National Coalition said "dozens of Druze young men" died in the shooting. It said an armed clash broke out "following an aggression by Nusra Front members."

Syrian state news agency SANA reported a "horrible massacre" that killed 30 people, including five members of the same family in Qalb Lawzeh.

Meanwhile, in southern Syria, Western-backed rebels entered for the first time the predominantly Druze province of Sweida, which has been spared Syria's four-year civil war that has killed more than 220,000 people.

Activists said the rebels entered the Thaala military air base outside the provincial capital, also named Sweida, capturing parts of it from government forces.

A Sweida resident told The Associated Press that the city was subjected to shelling on Thursday that killed one person and wounded six. It was not clear if the shells strayed from the fighting around the air base. The resident spoke on condition of anonymity fearing for his own safety.

The Druze have so far largely stayed out of the conflict in Syria but the developments in Idlib and Sweida have brought the community into the heart of the Syrian conflict, triggering calls to carry arms in self-defense. A 10th century offshoot of Shiite Islam, the Druze made up about 5 percent of Syria's prewar population of 23 million people. Neighboring Lebanon and Israel also have large Druze communities.

The political head of the Druze community in Lebanon, Walid Jumblatt, said a Druze religious council would hold an emergency meeting Friday. Jumblatt, who is an opponent of Assad, warned in a series of tweets against any inciting rhetoric over the violence.

But Wiam Wahhab, a Lebanese Druze politician close to Assad, called on all the Druze in Sweida to carry arms and defend their villages, and urged Assad's government to supply the residents with weapons.

"We need weapons in Sweida and any delay in supplying us with weapons, the Syrian state will be responsible," he said. "We want to fight with the state and with the army to defend ourselves."

At a press conference in Beirut, he said that Qatar and Turkey must be held responsible for the attack in Qalb Lawzeh because of their support for the Nusra Front.

In recent months, Assad's forces have suffered a string of defeats at the hands of rebels, a local Al Qaeda affiliate and the Islamic State group. There are concerns that the army would abandon Sweida, leaving residents to fend for themselves.

Syrian TV said one of its crews in Sweida came under rebel fire that killed the crew's driver and wounded reporter Anas al-Salman and cameraman Dergham Dbeisi.

Rebel Maj. Issam al-Rayyes, a spokesman for the Southern Front alliance, said the Thaala air base in Sweida province was captured by rebels on Thursday, two days after opposition fighters seized another key military base in southern Syria.

Ahmad al-Masalmeh, an opposition activist in southern Syria, said troops withdrew from Thaala to other parts of Sweida province. The Observatory said rebels took parts of the base.

But Syrian state TV denied the claims, saying government troops had repelled the attack on Thaala.

Also in the south, the Observatory and state TV said a Syrian army warplane crashed in Sweida. State TV said an investigation is underway to know what caused the crash.