Free Syrian Army fighters fire rockets towards forces loyal to Syria's President Bashar al-Assad in the northern countryside of Quneitra, Syria, June 17, 2015. Rebels in southern Syria announced a major offensive on Wednesday to capture remaining positions held by the Syrian military in Quneitra province, near the Israeli-occupied Golan Heights, where bombardments could be seen a short distance away. REUTERS/Alaa Al-Faqir TPX IMAGES OF THE DAY

By Sylvia Westall and Baz Ratner

BEIRUT/GOLAN HEIGHTS (Reuters) - The Syrian army said on Wednesday it had repulsed a major rebel offensive to capture remaining positions held by the Syrian military in Quneitra province, near the Israeli-occupied Golan Heights, where bombardments could be seen a short distance away.

Quneitra sits in a sensitive region around 70 kilometres (40 miles) southwest of the capital Damascus and has been the scene of frequent fighting between insurgent groups opposed to President Bashar al-Assad and the army backed by allied militia.

A Syrian army source told Reuters the army had beat back an insurgent assault to take over several hilltops and the government-controlled villages of Tel Shaar and Tel Bazaq, north of the deserted provincial capital of Quneitra.

"Army units have foiled efforts by the terrorist groups against these villages in the Quneitra countryside," the army source said, adding at least 200 insurgents were killed or wounded in the army operations.

State television footage showed several tanks and dozens of ground troops moving reinforcements through army-held villages in the lush agricultural border province, where rebels have made gains in the last two years.

Rebel spokesman Issam al-Rayes wrote on Twitter that an alliance of insurgent groups, which did not include al Qaeda's Syria wing Nusra Front, were taking part in the offensive under the banner of the rebel Free Syrian Army.

Nusra has fought in southern Syria but is not thought to be the main insurgent force there, unlike in other parts of the country.

Rayes later told Reuters the attempt to seize remaining army strongholds in the province, following several failed efforts, also targeted the army's main Liwa 90 base. "This is an attempt to end the presence of the regime in the province," he said.

The insurgents were eyeing the city of Baath, the province's main administrative centre and the town of Khan Arnba, the two main urban centres still in the hands of the government.

Dislodging the army from Quneitra would open a supply route to rebels south of Damascus in the opposition-controlled western Ghouta, from where they could target Assad's seat of power.

"We are aiming to destroy the first line of defence of the army around Damascus in this area," Rayes said.

Syrian Army Chief of Staff General Ali Ayoub earlier toured several frontlines in the Damascus countryside where the army was fighting insurgents and was quoted by state media as telling troops a relentless war against jihadist fundamentalist "Takfiris" would be waged until they were defeated.

A Reuters photographer watching from the Israeli-occupied Golan said there had been heavy shelling since early Wednesday in the Quneitra area. At one point he saw smoke rising from 13 bombardments. Shooting could also be heard in the distance.

It was not clear which groups were taking part.

Later, rocket alarms sounded in the Golan Heights. Tanks on the Syrian side could be seen firing and there was the sound of helicopters overhead.

The Britain-based Syrian Observatory for Human Rights monitoring group reported clashes between the Syrian military and insurgents including Islamist factions in northern Quneitra.

The Observatory's head Rami Abdulrahman said a handful of combatants had been killed on both sides since Tuesday.

Insurgents fighting in Sweida province further east had failed during recent fighting to capture a main road to Damascus and it was not clear whether they could secure a route to the capital in this latest offensive, he said.

Different groups, including the hardline Islamic State and Nusra Front, have been putting Assad under heavy pressure in various parts of the country in the past two months.

Another insurgent alliance including Nusra Front has taken hold of the northwestern Idlib province, edging closer to Assad's coastal stronghold, while Islamic State fighters overran the central city of Palmyra last month.

The government says it can defend important stretches of territory in Syria's populous west and the deputy foreign minister told Reuters last week that Damascus was safer than towards the start of the conflict, which grew out of protests against Assad in 2011.

The army also said it resisted a rebel attack on the Hay al Rashdeen district in government-controlled western Aleppo, which insurgents later said they had captured. Residents of the area reported heavy aerial bombing of the area.

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