BEIRUT/ANKARA: ISIS fighters have seized villages close to the city of Aleppo from rival insurgents, an activist group said on Friday, despite a Russian air-and-sea campaign that Moscow says has targeted the militant group.
The Russian defense ministry said airstrikes on rebel positions in northern Syria had killed 300 anti-Assad insurgents in nearly 70 sorties over the last day. There was no independent confirmation of the death toll.
The RIA news agency said 200 insurgents were killed in an attack on the Liwa al-Haqq rebel group while 100 were killed in Aleppo. Two ISIS field commanders were amongst the dead, the defense ministry was quoted as saying.
The Syrian Observatory for Human Rights, which monitors the fighting on the ground, 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 one of its generals had been killed late on Thursday near Aleppo, once Syria's most populous city. Iran, like Russia an ally of President Bashar Assad, says it has advisers in the country.
ISIS is now within 2 km (1 mile) of government-held territory on the northern edge of Aleppo which has suffered widespread damage and disease during the four-year 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-ISIS rebels near the heartland of Assad's minority Alawite sect, an area vital to his survival.
As the operation in the west pushed ahead, ISIS said its fighters had captured five villages in its northern offensive and killed more than 10 soldiers or militiamen.
The British-based Observatory said it was the biggest advance by ISIS since it launched an offensive against rival rebels in the Aleppo countryside near the Turkish border in late August.
"ISIS has exploited the Russian air strikes and the preoccupation of the (rebel) Free Syrian Army in its battles in Hama, and advanced in Aleppo," said one rebel commander with fighters in the region.
Russian warplanes and warships have been bombarding targets across Syria for 10 days in a campaign Moscow says is targeting ISIS fighters, who control large parts of eastern Syria and of neighboring Iraq.
But the campaign appears to have mainly struck other rebel groups, some of which had been battling to stop the ISIS advance across Aleppo province. The Russian defense ministry said it flew 67 sorties in the last 24 hours.
One of those groups, Liwa Suqour al-Jabal, said Russian strikes destroyed their main weapons depot this week. Liwa Suqour al-Jabal is one of a number of rebel groups that has received military support from the United States and Assad's Gulf Arab enemies.
Russian and U.S. warplanes are now flying missions over the same country for the first time since World War Two risking incidents between the two air forces and their fast jets.
U.S. President Barack Obama is set to overhaul Washington's approach to supporting Syrian rebels after this year's troubled launch of a military training program and is expected to speak on the matter within hours.
Seeking to underline the dangers of the Russian operation, U.S. officials said four Russian cruise missiles fired from a warship in the Caspian Sea had crashed in Iran which drew a swift denial from Russia that the rockets hit their targets.
U.S. Defence Secretary Ash Carter said, however, on Friday in London that the United States had indications that Russian cruise missiles did malfunction.
French Rafale warplanes attacked an ISIS training camp in their stronghold of Raqqa overnight.
"We struck because we know that in Syria, particularly around Raqqa, there are training camps for foreign fighters whose mission is not to fight ISIS on the Levant but to come to France, in Europe to carry out attacks," said French Defense Minister Jean-Yves Le Drian.
France launched its first air strike in Syria on Sept. 27, destroying an ISIS training camp near Deir al-Zor in the east of the country. Le Drian said that ISIS was France's "main enemy" and that Russian strikes were mostly hitting Assad's opponents in Syria and not ISIS targets.
The Observatory reported a new wave of Russian airstrikes in the west on Friday morning on Hama and Idlib, apparently in support of the ground offensive against anti-Assad rebels.
The offensive has focused around the Ghab Plain, next to Syria's western mountain range which forms the Alawite heartland and the important strategic main north-south highway running north from Hama towards the cities of Idlib and Aleppo.
Securing those areas would help consolidate Assad's control over Syria's main population centers in the west of the country, far from the ISIS strongholds in the east.
Alongside the Russian air-and-sea campaign, regional officials have told Reuters that hundreds of Iranian troops have arrived in Syria since late September to support the Syrian army and Lebanese Hezbollah fighters.
Senior Iranian officials have been in Syria for several years as military advisers, while Moscow has maintained a naval facility in the Syrian Mediterranean port of Tartous which it is using to supply its forces along with a base at Latakia.
The IRGC said one of its most senior generals, Hossein Hamedani, was killed near Aleppo late on Thursday. Hamedani was a veteran of the 1980-88 Iran-Iraq war and was made deputy chief commander in 2005. Several senior Guard commanders have been killed in Syria.
Iranian lawmaker Esmail Kosari said Hamedani had played an important role preventing rebel fighters seizing the capital Damascus earlier in Syria's conflict, and had returned for a few days because of his deep knowledge of the country.
The Observatory, which monitors Syria's conflict through a network of sources in the country, said Hamedani was killed near Kweires air base, about 20 miles (35 km) east of Aleppo. The precise cause of his death was not given.
Kweires has been besieged by ISIS fighters.
The Syrian war has drawn in armed forces from world and regional powers. The United States and its allies have been waging a year-long air campaign against ISIS in Syria, while pushing to diplomatically edge Assad from power. The CIA has trained anti-Assad rebels in small numbers.
The United States has ruled out military cooperation with Russia in Syria, accusing Assad's ally Moscow of pursuing a "tragically flawed" strategy that would force it to limit military talks to basic pilot safety. It says Moscow's strategy of backing Assad would simply prolong the conflict.
Turkey said on Friday it was concerned about the potential for a fresh wave of Syrian migrants arriving at its border as a result of Russian airstrikes in Syria. The conflict has now killed 250,000 people, causing a refugee crisis in Europe and neighboring nations.
The violation of Turkish air space by two Russian warplanes last weekend brought the Syrian conflict across NATO's borders, but the government said that, as yet, no Russian delegation had been sent to Ankara to provide information on the incursions.
Responding to the Russian airstrikes on anti-Assad rebels, the BBC said Saudi Arabia was increasing supplies of weapons, including guided anti-tank weapons. It quoted a Saudi government official as saying the arms would go to three rebel alliances.