BEIRUT (AFP) - ISIS (Islamic State in Iraq and Syria) extremists battling for control of the Syrian town of Kobane suffered some of their heaviest losses yet in 24 hours of clashes and US-led air strikes, monitors said on Sunday.
At least 50 ISIS militants were killed in the embattled border town in suicide bombings, clashes with Kobane's Kurdish defenders and the air strikes, the Syrian Observatory for Human Rights said.
The Britain-based monitor also reported that the US-led coalition battling the ISIS group hit at least 30 targets in and around Raqa, the extremists' de facto capital.
There were no immediate details of a toll in the Raqa strikes, which the Observatory called one of the larger waves of raids by the coalition since it began its campaign in Syria in September.
Syrian regime strikes on Sunday killed at least 29 civilians, among them seven women and three children, the group said.
The deaths in Kobane came on Saturday after ISIS launched an unprecedented attack against the border crossing separating the Syrian Kurdish town from Turkey.
Kurdish officials and the Observatory alleged the attack was launched from Turkish soil, a claim dismissed by the Turkish army as "lies".
ISIS began advancing on Kobane on Sept 16, hoping to quickly seize the small border town and secure its grip on a large stretch of the Syrian-Turkish border, following advances it made in Iraq.
At one point it looked set to overrun the town, but Kurdish Syrian fighters, backed by coalition air strikes and an influx of Iraqi Kurdish peshmerga forces, have held back the group.
In Raqa province, the coalition carried out strikes against at least 30 ISIS targets on the northern outskirts of Raqa city and struck Division 17, a Syrian army base ISIS captured earlier this year.
Observatory director Rami Abdel Rahman said the strikes had caused casualties, but there was no immediate toll available.
"We can't say it's the largest set of raids they have carried out, but it's been a long time since we've seen this number of targets hit," he said.
The coalition began carrying out air strikes against the ISIS group on Sept 23, and stepped up raids in Kobane in a bid to prevent it falling to IS.
The coordinator of the coalition said earlier this week that at least 600 ISIS fighters had been killed in air strikes and that the group had made easy targets of its fighters by pouring them into Kobane.
"ISIL has in so many ways impaled itself on Kobane," said retired US general John Allen, using a variant of the name for ISIS.
But Syria's Foreign Minister Walid Muallem, speaking from Russia after meeting key regime ally President Vladimir Putin, said the air strikes were having little effect.
"Is Daesh (ISIS) weaker today after two months of coalition strikes? All the indicators show that it is not," he told the pan-Arab Al-Mayadeen news channel.
He said unless Turkey closed its border to extremists, the group would be unharmed by the air strikes.
Damascus has regularly accused Turkey of supporting "terrorism" because of its support for the Syrian opposition.
Turkey denies the allegations, but has made no secret of its backing for the opposition, with President Recep Tayyip Erdogan calling for Syria's President Bashar al-Assad to step down.
Despite their differences, Erdogan is set to receive Putin in Ankara on Monday for talks about the conflict, which began in March 2011 and has killed nearly 200,000 people.
The Syrian regime has kept up its deadly strikes, including raids that killed 21 civilians including seven women and two children in Jassem in southern Daraa province on Sunday.
Regime strikes in Andan village in the northern province of Aleppo killed eight civilians including a child, the Observatory said.
Abdel Rahman said the Al-Qaeda-linked Al-Nusra Front executed 13 opposition fighters in Kawkaba village in the northwestern province of Idlib.
"Al-Nusra stormed the village after battles with opposition fighters and told those still there to surrender," he said.
"But one of them shot dead a Nusra commander and Al-Nusra then executed the 13 opposition members who were there."