At least 40 people have been killed in twin explosions near religious shrines frequented by Shiite pilgrims in the Syrian capital, Damascus, according to Syria's interior minister and media reports.

Here's your evening update.

Islamic State militants launched a new attack on the besieged city of Deir el-Zour today - in the most fierce fighting in a year, the Syrian government and opposition activists said.

Russia has warned the US against carrying out any attacks on Syrian government forces, claiming there would be repercussions across the Middle East.

Islamic State militants have killed dozens of government forces in wide-scale attacks on government-held areas of the eastern city of Deir el-Zour, Syrian opposition activists said.

The Syrian government has agreed to allow humanitarian assistance into three beleaguered villages following reports of deaths from malnutrition in that part of the country, a UN official has said.

US-led coalition aircraft launched nine missiles on a Syrian army camp in the eastern city of Deir el-Zour, killing three soldiers and wounding 13, according to the Syrian government.

An unseasonal sandstorm has swept across the Middle East covering Beirut and Damascus with a blanket of yellow dust.

Islamic State militants are said to be advancing toward the historic city of Palmyra in central Syria, seizing an oil field and taking control of the water company on the outskirts.

US-led coalition air strikes on Syria have killed more than 500 people, mainly Islamic militants, since they began last month, activists said as fighting flared in the northern Syrian border town of Kobani.

Planes believed to have been sent by the US-led coalition have struck positions held by Islamic State militants near a Syrian border town that beleaguered Kurdish forces have been struggling to defend.

The US-led coalition has carried out several air strikes targeting Islamic State group positions in northern and eastern Syria, activists said today.

The US-led coalition attacking Islamic State in Syria has launched air strikes on its positions including wheat silos in the country's east, activists said today.

Air strikes have targeted oil installations and other facilities in territory under the control of Islamic State (IS) militants in eastern Syria for a second consecutive day, activists have said.

US-led air strikes have targeted Syrian oil installations held by the Islamic State group, killing nearly 20 people, as the militants released dozens of detainees in their de facto capital, activists said.

Syrian government forces have launched a counter-attack to recapture a gas field seized by Islamic extremists, activists said, as the death toll from three days of fighting there rose to more than 200.

Sixteen people, including three civilians, have been killed in air strikes by the Syrian army against an eastern town which was captured by fighters from an al Qaida breakaway group a day earlier, according to activists.

A car bomb has exploded in eastern Syria near the border with Iraq, killing at least five people including a local rebel commander, activists say.

Syrian president Bashar Assad has declared a general amnesty for prisoners in the country, state media reported.

Two trucks carrying food and medical supplies into rebel-held neighbourhoods in the central Syrian city of Homs turned back under heavy fire, leaving four paramedics wounded as a ceasefire faltered.

Syrian rebels have attacked a village in the country’s east, killing dozens of Shiites, mostly pro-government fighters, activists said.

Syrian rebels have shot down a military helicopter in the country’s east, killing eight government troops on board.

Heavy fighting for control of the international airport in the northern Syrian city of Aleppo and a major military air base nearby has killed some 150 rebels and government soldiers over the past two days, activists say.

A bomb blast in a Palestinian refugee camp in Damascus killed four people and seriously wounded a member of a faction that has backed Syrian President Bashar Assad in the country’s bitter civil war, activists said today.

Syrian rebels strengthened their hold on an oil-rich province bordering Iraq today, activists said, capturing a key military base which was considered one of the last bastions for President Bashar Assad’s loyalists in the strategic region.

Syrian rebels have seized a key military base with artillery stockpiles in the country’s east, activists say.

A Syrian warplane flattened a three-storey building, suspected rebels detonated a deadly car bomb and both sides traded gunfire in hotspots across the country, leaving a United Nations-backed holiday truce in tatters on its second day.

Syrian troops have shelled rebel-held areas and clashed with anti-government gunmen in several parts of the country despite an internationally mediated ceasefire, according to activists.

Heavy fighting has preceded the dawn start of a proposed truce in Syria’s 19-month civil war, activists said.

A Syrian military helicopter has crashed in a rebellious suburb of Damascus, state-run TV says.

Government warplanes bombed a town in northern Syria today, killing at least 18 people, activists said, while the new UN envoy to the country acknowledged that brokering an end to the nation’s civil war will be a “very, very difficult” task.

The UN’s new envoy to Syria said today that president Bashar Assad’s regime should realise that the need for change is both “urgent” and “necessary” and that it must meet the “legitimate” demands of the Syrian people.

Syrian activists have claimed rebels shot down a government warplane over the northern province of Idlib on Thursday, the second time in a week that opposition fighters claimed to have brought down an aircraft in the escalating civil war.

Syrian rebels waged fierce battles with regime troops in a town along the Iraqi border today, capturing a string of security posts and the local police headquarters despite heavy government shelling and bombing runs by warplanes, activists said.

Dozens of government tanks have converged on Syria’s largest city as president Bashar Assad marshalled his forces to stamp out a five-day rebel fight to wrest Aleppo from the regime’s grasp.

Syria’s elite Republican Guard has clashed with rebels outside Damascus in some of the most intense fighting involving the special forces since the uprising against president Bashar Assad began.

At least 10 people were killed when a mortar round hit an anti-government demonstration in an eastern Syrian city today, activists said.

International envoy Kofi Annan said today he was “gravely concerned” about the latest violence in Syria, citing shelling of opposition areas in Homs and reports of mortar, helicopter and tank attacks near the coast.

Syrian troops and helicopters are clashing with rebels in the central town of Rastan, activists said today.

Syrian troops have heavily shelled a rebel-held neighbourhood in the flashpoint central city of Homs as the military appeared to be readying to storm the area, activists said.

Syrian troops are shelling the rebel-held neighbourhood of Khaldiyeh in the central city of Homs, according to activists.

Syria has granted permission for aid workers to enter four hard-hit provinces, the United Nations said today.

The UN's top human rights body has voted overwhelmingly to condemn Syria over the slaughter of more than 100 civilians last week.