BEIRUT (AFP) - Around 400 men, including rebels and draft evaders, from besieged areas of the Syrian city of Homs who surrendered to the authorities fear they may be held indefinitely, activists said Tuesday.

Evacuations began in February in a UN-supervised humanitarian operation during which around 1,400 people have left the war-battered rebel areas.

The operation was initially intended to allow women, children and the elderly to leave the Old City, where people have been surviving on little more than herbs for nearly two years, but scores of men also left.

Two weeks ago, another 300 men - mainly rebel fighters and draft evaders - also left, including a civilian activist who identified himself as Omar.

"There was a promise that the army defectors would be released if they handed in their weapons, and they did. There was talk that we draft evaders would be released too, but till now, there is nothing," said Omar.

He and the other men are all still being held at a former school called Al-Andalus, located in Homs city.

Omar said they were being held in good conditions, "but we don't know anything about what will happen to us. We are waiting and waiting."

In an email to AFP, the UN delegation in Syria said its resident coordinator Yacoub El Hillo visited the Al-Andalus facility on April 7 and 8, and "met with the group of evacuees".

According to the UN, no information has been provided by the Syrian authorities as to when all the men will be released.

During Hillo's visit, the UN delegation met with Homs Governor Talal al-Barazi.

"It was agreed in the meeting at Al-Andalus facility that UN agencies will provide humanitarian supplies to NGO Shabab al-Khair for those who continue to await registration," said the UN.

Hillo "discussed cases of disappearance and detention with the governor. It was clarified that names of those regularised have been distributed to all entities and checkpoints in Homs and to Damascus for countrywide dissemination," it said.

The governor had attributed the delays in clearing the remaining detainees to "administrative procedures".

"The governor indicated that 92 evacuees from the old caseload remain in Al-Andalus facility, some 25 of who have been cleared but opted to remain in the facility."

Barazi himself told AFP: "Every day some 10 to 25 men leave (besieged) Old Homs and hand over their weapons. We welcome them in a hospitality centre for as long as we need to study their situation.

"Each person has a specific case. Some stay (in Al-Andalus) for two days, others for a week, and others for longer. Last Friday, we cleared 54 men."

The detainees' fears come amid a major escalation in fighting around the Old City. For the first time since last summer, the army entered the besieged area on Tuesday under cover of fire.