Syrian rebels fighting forces loyal to President Bashar al-Assad have taken over the Quneitra crossing on the Israel-Syria ceasefire line in the Golan Heights, army radio reported on Thursday, quoting military officials.
The United Nations also confirmed that there were "incidents" along the ceasefire line.
"The IDF (Israel Defence Forces) confirms that Quneitra crossing has fallen to the rebels," the radio said.
Contacted by AFP, a military spokesman refused to comment on the report, which refers to a crossing point in the central part of the strategic plateau.
The Israeli radio station said fierce fighting was still under way in the actual town of the same name, which lies close to the crossing.
Israeli security sources confirmed there were exchanges of fire in the area of the crossing, but said it was not yet possible to say whether it had been taken over.
An Israeli military source told the BBC that Syrian army tanks were deployed to retake Quneitra.
"They are exchanges of fire there," another source told AFP. "The incident is ongoing so it's very hard to say who is in control there."
He said the military had warned farmers not to approach the area and that an unspecified number of Syrian government troops had been taken to a hospital in occupied Palestine for treatment.
"There are apparently also those who are badly injured among the Syrian (army) forces who have been taken to hospital in Safad," he said.
A spokeswoman for Ziv hospital in Safad was unable to confirm or deny the report, referring all inquiries to the military.
In the past three months, at least 16 people wounded in the civil war which has gripped the country have crossed the border and received medical treatment at the hospital.
Israel seized a large section of the strategic plateau from Syria in the 1967 Six-Day War and annexed it in 1981, in a move never recognized by the international community.
Israel and Syria are still technically at a state of war.