Fighters from the Islamic State of Iraq and the Levant (ISIL) have advanced deeper into the Syrian town of Kobane, taking control of more than 40 percent of territory, according to a group monitoring the violence.

The UK-based Syrian Observatory for Human Rights, which monitors the country's civil war, said on Friday that the self-declared jihadist group had "taken at least 40 percent [of the town]".

Rami Abdulrahman, who runs the Syrian Observatory through a network of activists on the ground, said ISIL were in almost complete control of the "security quarter", which is home to administrative buildings and the police station used by the local government.

Al Jazeera's Stefanie Dekker, reporting from Suruc on the Turkey-Syria border, said ISIL were making gains in the eastern side of Kobane, where they also managed to take over a security headquarters.

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However, a Kurdish military official earlier denied any major advance by the group, telling the Reuters news agency that clashes between ISIL and Kurdish fighters were still ongoing.

Ocalan Iso, deputy head of the Kurdish forces, said ISIL was still bombarding the town centre with mortars, showing that its fighters had not extended their control over more than 20 percent of the town.

"There are fierce clashes and they are bombing the centre of Kobane from afar," he said.

ISIL's advance has brought the frontline to just 1.3km from the Syrian-Turkey border, despite US-led air strikes targeting the group's positions.

The US military said it conducted nine air strikes against ISIL positions in Syria in the past two days, including seven near Kobane, destroying two training facilities, vehicles and two small units.

Looming 'massacre'

Despite intensified air strikes, the UN envoy to Syria has warned of a looming "massacre" in Kobane, as thousands of civilians remain trapped in the besieged town.

Staffan de Mistura said on Friday that a UN analysis of the situation on the ground showed that only a small portion of the town remained open for people to enter or flee Kobane.

If the town falls to ISIL, "we know what they are capable of doing", said the Italian-Swedish diplomat, who was appointed to the UN post in July.

The civilians of Kobane "will be most likely massacred", de Mistura said.

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He said there were about 500 to 700 elderly people and other civilians trapped there while 10,000 to 13,000 remained stuck in an area nearby, close to the border.

Activists told Al Jazeera on Friday that at least eight civilians were killed in a government air strike in the village of Al-Harra in Deraa province.

The Syrian National Coalition, Syria's main Western-backed opposition group, has accused President Bashar al-Assad of "openly exploiting" the coalition's war against ISIL to continue killing Syrians.

On the diplomatic front, the head of the US-led coalition, retired General John Allen, and US pointman on Iraq, Brett McGurk, completed a two-day visit in Turkey on Friday to press the NATO ally to engage militarily against ISIL.

Asked if the meetings - attended by Ahmet Davutoglu, Turkish prime minister, and military officials - had led to "progress", Marie Harf, State Department deputy spokeswoman, said yes.

She said "Turkey has agreed to support, train and equip efforts for the moderate Syrian opposition" - one of the main components of US strategy in Syria unveiled on September 10 by US President Barack Obama.

Allen and McGurk also met leaders of the Syrian opposition in the Turkish capital Ankara.

Harf confirmed that a US military team would visit Turkey next week to meet their Turkish military counterparts.

Meanwhile, in Washington DC, Hakan Fidan, head of the Turkish National Intelligence Organisation, met William Burns, with US deputy secretary of state, at the State Department, a spokeswoman told AFP news agency.

Fidan also met Lisa Monaco, Obama's top counter-terrorism adviser, to "to discuss ways to deepen already close counterterrorism cooperation and to further integrate Turkey's unique capabilities into the international coalition against ISIL".

Monaco "expressed appreciation" for Turkey's support and "the importance of accelerating Turkish assistance," according to a statement from the White House.

Source: Al Jazeera and agencies