BEIRUT: A car bomb explosion near a gas plant in Syria's Homs province Monday killed nine people including four soldiers, activists said, updating an earlier toll.
ISIS claimed responsibility for the attack and said the two bombers were killed.
State news agency SANA confirmed the attack but said that troops had captured the bombers.
"Five employees and four regime troops guarding the Firqlos gas plant were killed in a car bomb blast near the facility in the east of Homs province," said the Syrian Observatory for Human Rights.
The explosion also wounded 15 people.
It took place "at the start of the working day", the Britain-based group added.
SANA, quoting a military source, said "guards captured the two terrorists who detonated the pick-up truck at the entrance to the plant while they were trying to flee."
ISIS said the two men, both Moroccan, had died.
The jihadis have targeted oil and gas facilities in Iraq and Syria as the group seeks funds for its fight to seize territory for a self-proclaimed Islamic "caliphate".
In November, Syrian troops backed by pro-regime militiamen recaptured the Shaer gas field in central Homs province, a week after ISIS fighters overran parts of the complex.
ISIS killed some 350 regime troops and loyalist militiamen, as well as gas plant workers, during its attempt to take Shaer.
Elsewhere in Syria, the Observatory said the number of ISIS members killed fighting Kurdish forces in the flashpoint town of Kobani Sunday had risen to 18.
Another two ISIS suicide attackers also died, as did 10 members of the Kurdish People's Protection Units (YPG), it said.
The jihadis launched a major offensive in mid-September to try to capture Kobani, and at one point controlled more than half the town, known in Arabic as Ain al-Arab.
But backed by US-lead coalition airstrikes on ISIS positions, Kurdish forces have regained control of several neighborhoods.
Coalition aircraft struck ISIS targets in Kobane Sunday night, the Observatory said, and a Pentagon statement said 10 strikes hit the area Monday.
More than 1,000 people are reported to have been killed in the battle for the town, most of them jihadis.