Islamic State forces have made further advances on another day of intense fighting in the Syrian city of Kobane.
The militants have captured the headquarters of the Kurdish fighters, and are closing off the final route out of the blasted urban area.
The UN envoy to Syria, Staffan de Mistura, has warned that the remaining civilians in Kobane are likely to be massacred if the town falls.
The BBC reports it is estimated there are 700 Kurds in the city, and as many as 14,000 who have fled towards the closed Turkish border.
The US-led coalition has conducted more air strikes against IS but the White House says it may not be able to prevent the fall of Kobane.
Kurdish forces, who are being helped by US-led coalition strikes, say they urgently need more weapons to push back the militants' advance in the city.
Staffan de Mistura said except for one narrow exit point, Kobane is surrounded by Islamic State.
He said hundreds of mainly elderly civilians were still inside the city centre and another 10,000 to 13,000 people were trapped between the town and the border.
Mr de Mistura said the civilians will "most likely be massacred'' if Kobane falls to Islamic State, warning the UN does not want to see another Srebrenica - where thousands of Muslim men and boys were killed by Bosnian Serb forces in 1995 during the Bosnian conflict.
He also urged Turkey to allow in volunteers to Syria to defend Kobane from Islamic State militants.
A Syrian Kurdish source inside Kobane has denied reports that IS has taken almost complete control of the town's "security quarter" - where the Kurdish civilian headquarters are based.
The source told the BBC that Kurdish fighters remained in control of two administrative buildings in the east of the town, saying that "heavy fighting has reached the 'security quarter' but it has not fallen yet".
Earlier, the UK-based Syrian Observatory for Human Rights said the jihadists had seized the main headquarters of the Kurdish military and civilian authorities.