More than 300 Islamic State militants surrounded in a tiny area in eastern Syria are refusing to surrender to US-backed forces and are trying to negotiate an exit, Syrian activists and a person close to the negotiations said on Monday.The extremists are bottled up in the village of Baghouz, where they are hiding among hundreds of civilians and preventing them from leaving. The stalling tactics are likely to further delay a declaration of the end of the ISIS group's self-proclaimed caliphate, which the US-backed Syrian Democratic Forces were hoping to make last week.A person familiar with the negotiations said the militants are asking for a corridor to the rebel-held northwestern province of Idlib, and demand that they be allowed to leave along with the evacuated civilians. He spoke on condition of anonymity because he was not authorised to speak about the talks, which he described as taking place indirectly.The Britain-based Syrian Observatory for Human Rights, an activist group that monitors the civil war in Syria, said another request by ISIS to be evacuated to neighbouring Iraq was also rejected. ISIS released 10 SDF fighters it had been holding on Sunday, but it was not clear what, if anything, the extremists would get in return, the Observatory said.The speck of land in Syria's remote eastern desert, near the border with Iraq, is all that remains of a self-styled caliphate that once sprawled across a third of both countries and included several major towns and cities.In that tiny patch on the banks of the Euphrates River, the militants are holed up in what SDF officials describe as a small tented village atop a network of tunnels and caves. There are civilians inside as well, possibly including hostages.The SDF and the US-led coalition have been fighting ISIS in the surrounding region since September. In recent years, they and other forces have steadily driven ISIS from nearly all the territory it once controlled, in battles that have killed tens of thousands of people and left entire towns and neighbourhoods in ruins.The DeirEzzor 24, an activist collective in eastern Syria, said several trucks loaded with food entered ISIS-held areas in Baghouz on Monday. It also reported the release of the SDF fighters, without saying whether there was a quid pro quo.DeirEzzor 24 said the truce reached last week has been extended for five more days as of Sunday. It added that in return several trucks loaded with food entered the ISIS-held area on Sunday.At least 62 people have died in recent weeks, mainly from exhaustion and malnutrition, after making their way out of militant-held territory, the International Rescue Committee said. Spokesperson Paul Donohoe said two-thirds were children under the age of one. He said they either died along the way or soon after arriving at a camp for the displaced.Over 30 000 people who left the last IS-held areas have arrived at the al-Hol camp in Syria's northern Hassakeh province in the last few weeks, raising the overall population of the camp to almost 42 000.Elsewhere in Syria, two bomb blasts went off in the northwestern city of Idlib, killing at least 13 people, Syrian opposition activists and paramedics said.The Observatory said the blasts in the Qusour neighbourhood during rush hour on Monday killed 17 people and wounded about 50. The Edlib Media Center, an activist collective, said the bombings killed 13 and wounded dozens.The first blast occurred in the early afternoon and another followed seconds later. The opposition's Syrian Civil Defense, a group of volunteer first responders, said one of its members was wounded.The city of Idlib is controlled by al-Qaeda-linked militants, who have wide influence in northern Syria.The city has been hit with bombings in recent months that killed or wounded scores of people.