 "Islamic State")
Islamic State fighters have seized villages close to the northern city of Aleppo from rival insurgents, a monitoring group said, despite an intensifying Russian air-and-sea campaign that Moscow says has targeted the militant group.
News of the advance came as the United States announced it was largely abandoning its failed programme to train moderate rebels fighting Islamic State and would instead provide arms and equipment directly to rebel leaders and their units on the battlefield.
The Obama administration is grappling with a dramatic change in the four-year-old Syrian civil war brought about by Moscow's intervention in support of President Bashar al-Assad.
The Pentagon said it expected to hold new talks with Russia's military on pilot safety in Syria's war as soon as this weekend, as the former Cold War foes seek to avoid an accidental clash as they carry out rival bombing campaigns.
The Russian defence ministry said stepped-up air strikes on rebel positions in Syria killed 300 anti-Assad rebels and that it hit 60 Islamic State targets over the last day. There was no independent confirmation of the death toll.
About 200 insurgents were killed in an attack on the Liwa al-Haqq group in Raqqa province while 100 died in Aleppo, the defence ministry said. Two Islamic State commanders were among the dead in Russia's most intense raids since it launched strikes in Syria 10 days ago. In previous updates Russia has reported hitting 10 targets daily.
However, the Syrian Observatory for Human Rights, which monitors the fighting, said there had been no significant advances by government forces backed by allied militia in areas where ground offensives were launched this week. "It's back and forth," said Rami Abdulrahman, director of the Observatory.
Iran's elite Revolutionary Guard Corps said separately that one of its generals had been killed near Aleppo, once Syria's most populous city. Iran, like Russia an Assad ally, says it has advisers in the country.
Islamic State is now within 2 km (1.2 miles) of government-held territory on the northern edge of Aleppo, which has suffered widespread damage and disease during the civil war that erupted in the wake of protests against Assad.
Syria's military, backed by Russia, Iran and allied militias, has launched a major attack in Syria's west to recapture land lost to non-IS rebels near the heartland of Assad's minority Alawite sect.
