Islamic State (IS) militants have
entered the key Syria-Turkey border town of Kobane and taken control of three
districts after street-to-street fighting with Syrian Kurd defenders.
Local officials said about 2,000 civilians fled to the Turkish border.
Taking Kobane, besieged for three weeks, would give IS control of a long stretch of the Syrian-Turkish border.
More than 160,000 Syrians, mainly Kurds, have fled the town.
Earlier a local official in Kobane, Idriss Nassan, told the BBC that the town would "certainly fall soon".
He confirmed IS was now in control of Mistenur, the strategic hill above the town and that there was heavy shelling. Kobane is now besieged on three sides.
Aircraft from the US-led coalition are reported to have conducted further strikes on Tuesday morning, though the targets were unclear.
Large explosions were heard by reporters monitoring from the Turkish side of the border and plumes of smoke could be seen.
There are also reports that IS fighters entered parts of the south-west of the town overnight.
Clashes, including sniper fire, were reported by the Syrian Observatory for Human Rights activist group.
The view of an IS flag from the
Turkish side of the border near Kobane
'Limited weapons'
Karwan Zebari, a representative of the Kurdish regional government in the US,
told the BBC it would be catastrophic if IS seized control of the town.
"If this continues, if there's no international aid, military aid arriving for the residents of Kobane and these Kurdish fighters that are fighting in Kobane, it could fall into the hands of IS," he said.
He urged Turkey to take action in support of the residents of Kobane.
"I think Turkey's interests, national security, is at stake here as well. It's important that Turkey steps up and assists these Kurdish fighters in repelling this IS momentum."
Speaking on Monday, Asya Abdullah, a co-leader of the Kurdish Democratic Union Party representing Syrian Kurds in Kobane, described the fighting to the BBC's Newshour programme.
She said: "There are still thousands of civilians in the city and IS is using heavy weapons. If they are not stopped now, there will be a big massacre.
"They have surrounded us almost from every side with their tanks. They have been shelling the city with heavy weapons. Kurdish fighters are resisting as much as they can with the limited weapons they have."
A Truck loaded with civilians
approaches the Turkish border
The US Central Command earlier confirmed an air strike on Monday by US-led forces had "destroyed two IS fighting positions south of Kobane" but Ms Abdullah said the strikes in the area were "ineffective".
She said: "[IS has] heavy weapons and tanks, that is why our resistance has limits and we need more air strikes."
Ms Abdullah said: "The rest of the world is silent about this imminent massacre."
"If this continues, if there's no international aid, military aid arriving for the residents of Kobane and these Kurdish fighters that are fighting in Kobane, it could fall into the hands of IS," he said.
He urged Turkey to take action in support of the residents of Kobane.
"I think Turkey's interests, national security, is at stake here as well. It's important that Turkey steps up and assists these Kurdish fighters in repelling this IS momentum."
Speaking on Monday, Asya Abdullah, a co-leader of the Kurdish Democratic Union Party representing Syrian Kurds in Kobane, described the fighting to the BBC's Newshour programme.
She said: "There are still thousands of civilians in the city and IS is using heavy weapons. If they are not stopped now, there will be a big massacre.
"They have surrounded us almost from every side with their tanks. They have been shelling the city with heavy weapons. Kurdish fighters are resisting as much as they can with the limited weapons they have."
A Truck loaded with civilians
approaches the Turkish border
Kurdish men appeal to the
Turkish military to help evacuate people from a village near Kobane
Mustafa Bali, a spokesman for Kurds in Kobane, told Agence France-Presse that
2,000 civilians had been evacuated on Monday and that all civilians had been
ordered to leave.The US Central Command earlier confirmed an air strike on Monday by US-led forces had "destroyed two IS fighting positions south of Kobane" but Ms Abdullah said the strikes in the area were "ineffective".
She said: "[IS has] heavy weapons and tanks, that is why our resistance has limits and we need more air strikes."
Ms Abdullah said: "The rest of the world is silent about this imminent massacre."
Analysis: Paul Adams, BBC News,
near the Syrian border
Turkey - a regional superpower with significant troops and armour in the area - seems extremely reluctant to intervene despite a government pledge to do whatever it takes to prevent Kobane from falling.
It wants the US-led coalition to agree on a number of things first, including setting up a no-fly zone and a buffer zone in northern Syria and, crucially, a renewed focus on getting rid of President Assad which remains Turkey's principle objective.
The Turks are at loggerheads with Washington on that objective and for those reasons, and because of the very bad blood that has existed for decades between Turkey and its own Kurdish population.
Turkey fought a bloody war against the Turkish guerrilla group, the PKK, that helps to explain why Ankara remains deeply reluctant to get engaged.
A steady stream of Turkish ambulances raced to and from the border, with many wounded people being treated in hospitals close to the frontier.
Turkish Kurds and refugees have clashed with Turkish security forces on the border for the past two days.
They are angry at Turkey's perceived inaction over IS in recent months, as well as its refusal to allow them to cross into Syria to fight.
Last week, Turkey pledged to prevent Kobane from falling to the militants and its parliament authorised military operations against militants in Iraq and Syria. But it appears to have taken no action so far.
Correspondents say Turkey is reluctant to lend support to the Kurdish forces in the town because they are allied to the PKK, banned as a terrorist organisation in Turkey.
- Kobane, known in Arabic as Ayn al-Arab, and the villages surrounding it were home to about 400,000 people, most of them Kurds
- Kurdish parties have governed the area since the Syrian army withdrew two years ago
- In the first half of 2014, IS seized control of neighbouring areas, leaving Kobane surrounded on three sides
- IS launched a major offensive on 16 September, prompting more than 100,000 people to flee to Turkey
