By John Davison and Tom Perry
AIN ISSA, Syria/BEIRUT (Reuters) - Islamic State is on the verge of defeat in Syria's Raqqa and the city may finally be cleared of the jihadists on Saturday or Sunday, the Syrian Kurdish YPG militia told Reuters.
A local official separately told Reuters that tribal elders from Raqqa were seeking to broker a deal where remaining Islamic State fighters, including foreigners, would leave the city, taking civilians with them as human shields.
The U.S.-led coalition however said it wanted the unconditional surrender of all IS militants in Raqqa.
Its spokesman said around 100 jihadist fighters had surrendered in Raqqa in the last 24 hours and had been "removed from the city", and it still expected difficult fighting "in the days ahead".
The Syrian Democratic Forces (SDF), backed by coalition air strikes and special forces, have been battling since June to oust Islamic State from Raqqa, formerly its Syrian de facto capital and a base where it planned attacks against the West.
The final defeat of Islamic State at Raqqa will be a major milestone in efforts to roll back the group's self-declared "caliphate" in Syria and Iraq, where earlier this year the group was driven from the city of Mosul.
"The battles are continuing in Raqqa city. Daesh (Islamic State) is on the verge of being finished. Today or tomorrow the city may be liberated," YPG spokesman Nouri Mahmoud told Reuters by telephone.
Omar Alloush, a member of the Raqqa Civil Council, said the 100 Islamic State fighters who had already surrendered had been convinced to do so during talks with the tribal elders. The council was set up to run Raqqa after it is freed from IS.
"Others didn't surrender, so now they're looking for a plan where they (IS) leave and take civilian hostages with them to another place far from the city, and then release the civilians," he told Reuters in an interview in Ain Issa, north of Raqqa. The IS fighters would go to remaining territory held by the group in Syria, he said.
The deal could happen as soon as Saturday, he said.
A tribal leader said he expected the evacuation to take place on Saturday or Sunday.
Col. Ryan Dillon, the spokesman for the U.S.-led coalition, said its position was that IS fighters must surrender unconditionally. The Raqqa Civil Council, the SDF and local leaders had been working on "local solutions", he added.
"Though we were able to present our side, those discussions happened between those entities and that's where the decisions were made," he said by phone.
"We still expect difficult fighting in the days ahead and will not set a time for when we think (Islamic State) will be completely defeated in Raqqa," he said, adding that around 85 percent of Raqqa had been liberated as of Oct. 13.
Around 1,500 civilians had been able to safely make it to SDF lines within the last week, he added.
The Syrian army, which is supported by Iran-backed militias and the Russian air force, declared another significant victory over Islamic State on Saturday, saying it had captured the town of al-Mayadin in Deir al-Zor province.
BUSES ARRIVE IN RAQQA
The Syrian Observatory for Human Rights, a UK-based organisation that reports on the war, said remaining Islamic State fighters were being transported out of Raqqa by bus under a deal between Islamic State, the coalition and the SDF.
There was no immediate comment on that report from the coalition or the SDF.
An activist group that reports on Raqqa, Raqqa Is Being Slaughtered Silently, said on its Facebook (NASDAQ:FB) page on Saturday that dozens of buses had entered Raqqa city overnight, having travelled from the northern Raqqa countryside.
The Observatory said Syrian Islamic State fighters and their families had already left the city, and buses had arrived to evacuate remaining foreign fighters and their families. It did not say where they would be taken to.
During the more than six-year Syrian war, the arrival of buses in a conflict zone has often signalled an evacuation of combatants and civilians.
The campaign against Islamic State in Syria is now focused on its last major foothold in the country, the eastern province of Deir al-Zor which neighbours Iraq.
Islamic State faces separate offensives in Deir al-Zor by the SDF on one hand, and Syrian government forces supported by Iranian-backed militia and Russian air strikes on the other.
In August, Islamic State fighters agreed to be evacuated from a Lebanon-Syria border area, the first time the militants had publicly agreed to a forced evacuation from territory they held in Syria.
But as the convoy moved towards Islamic-State territory in eastern Syria, coalition planes blocked its route by cratering roads, destroying bridges and targeting nearby Islamic State vehicles.
Civilians have been making perilous journeys to escape Islamic State-held areas as SDF forces advance. The SDF says it helps transport them away from the fighting after they flee.
The offensive to drive Islamic State out of Raqqa, its de facto Syrian capital which it seized in 2014, has long outlasted initial predictions by SDF officials who said ahead of an assault in June that it could take just weeks.