neighbouring Iraq, which the US military declared its top priority.
As fighting raged on several fronts, Al-Qaeda's deadly Yemen-based franchise urged Muslims worldwide to support the IS jihadists in Syria and Iraq.
The US commander overseeing the air war hailed "encouraging" signs in the efforts to defend Kobane, but said the town could still fall to extremists and that confronting IS in Iraq was the coalition's top focus.
"Iraq is our main effort and it has to be," General Lloyd Austin said.
Six US-led coalition air strikes hit IS positions in the east of Kobane on Friday, taking advantage of new coordination with the town's Kurdish defenders, the Syrian Observatory for Human Rights said.
The jihadist group has captured large parts of Syria and Iraq, committing atrocities and declaring an Islamic "caliphate".
The Observatory said IS fighters were now being trained to fly three fighter jets seized from the Syrian military.
It said that former Iraqi army officers who once served under Saddam Hussein were supervising the training at the Jarrah military airport in the northern province of Aleppo.
In Iraq security forces on Friday fought IS jihadists on two fronts -- in the strategic city of Ramadi, west of Baghdad, and near militant-held Tikrit to the north.
Ramadi, the capital of Anbar province, is one of a dwindling number of areas in the region where pro-government forces still hold ground, and its loss would be a major blow for Baghdad.
Iraqi government forces launched an offensive Friday north of Tikrit, one of a string of mainly Sunni Arab towns north and west of Baghdad that the jihadists seized in June.
Iraqi troops have been struggling to retake and hold ground, despite the US-led air bombardments.
But the US military said that Baghdad was not under "imminent threat" from the jihadists, despite a string of deadly car bombs in the Iraqi capital.
"There are not masses of formations of (IS) forces outside of Baghdad about to come in," spokesman Rear Admiral John Kirby said.
- 'Bodies in streets' -
Kobane district chief Anwar Muslim said the US-led strikes had destroyed many IS vehicles and artillery pieces.
"You can see their bodies (IS jihadists) in the streets... Our forces are reinforcing their defensive positions," he told AFP.
Muslim said sniper and mortar fire from jihadists was preventing authorities from evacuating civilians caught up in the battle.
"Their situation is difficult," he added.
Washington revealed it held its first direct talks last weekend with the main Syrian Kurdish group whose forces have been battling IS.
Earlier contacts with the Kurdish Democratic Union Party (PYD) had all been handled through intermediaries, as the group has close ties with the rebel Kurdistan Workers Party (PKK) -- which is on the US terror blacklist -- over the border in Turkey.
The PYD has been appealing urgently for weapons to resupply its outgunned fighters in Kobane, but Washington said it was too early to discuss the request.
The Kurds claimed to have pushed IS back in parts of Kobane as the coalition intensified its air strikes in recent days.
- Call to mujahedeen -
Warplanes from five Arab states of the Gulf -- Bahrain, Jordan, Saudi Arabia, Qatar and the United
Arab Emirates -- have since last month taken part in US-led air strikes on IS targets in Syria.
Al-Qaeda in the Arabian Peninsula, classified by the United States as the network's deadliest franchise, in a statement released on Friday urged Muslims not to participate in the battle against IS.
"We urge all mujahedeen (Muslim fighters) to set aside their differences and inter-factional fighting and move instead against the crusade targeting all" jihadists, it added.
Coalition forces have now carried out more than 100 air strikes near Kobane since September 27.
The month-old IS assault on the area has sparked an exodus of some 200,000 mainly Kurdish refugees across the border, where the town's plight has stoked nationalist sentiment among Turkey's own large Kurdish minority.
More than 180,000 people have been killed in Syria since an uprising against President Bashar al-Assad's regime began in 2011, escalating into a multi-sided civil war.
At least 15 civilians, including three minors, were killed in Syrian regime air raids on a rebel-held town near the capital on Friday, the Observatory said.