By Erika Solomon
BEIRUT, Feb 6 (Reuters) - Syria said it reached a deal with the United Nations on Thursday to allow "innocent" civilians to leave the besieged rebel-held old city of Homs, potentially the first positive result after deadlocked peace talks in Switzerland last week.
However, U.N. officials initially declined to comment on the reported deal, and it was not clear whether the offer would come with sufficient guarantees for the safety of those trapped in the besieged area to satisfy aid agencies.
The government's announcement of the agreement came hours after rebels declared a new offensive in the northern province of Aleppo, in response to an escalated air assault by government forces trying to recapture territory and drive residents out of opposition-held areas.
President Bashar al-Assad's forces have used a siege tactic to surround and try to starve out rebels holding strategic areas, a technique increasingly copied by rebels as well.
The siege of the old city of Homs has gone on for over a year, and activists say some 2,500 people are trapped inside the area struggling with hunger and malnourishment. They represent only a small fraction of besieged Syrians across the country in desperate need of aid.
"The agreement will allow innocents civilians surrounded in the neighbourhoods of Old Homs - among them women and children, the wounded and the elderly - an opportunity to leave as soon as the necessary arrangements, in addition to offering them humanitarian aid," said a Syrian foreign ministry statement, cited on Syria TV.
"It will also allow in aid to civilians who choose to stay inside the old city."
Delegates from Syria's warring sides met face to face for the first time at the "Geneva 2" peace conference last week and were unable to agree anything, even a humanitarian deal for Homs that diplomats had hoped could be a relatively easy first step.
A second round of talks is scheduled for next week.
The government statement did not elaborate on who would be considered "innocent".
Rebels have rejected similar offers to evacuate women and children in the past because of fear for the fate of any men left behind. Dozens of men disappeared after a similar deal reached in Mouadamiya, west of Damascus.
RIA news agency from Assad's ally Russia quoted an unnamed official at Syria's Defence Ministry saying rebel fighters were keeping civilians in the area as human shields.
"As for civilians, we are not holding them up or refusing them humanitarian aid but the terrorists are the problem," it quoted the source as saying. "Terrorists are claiming that there are only civilians in the Old City who need humanitarian aid. In fact, it's terrorists who are mainly there, including foreign militants, using small groups of civilians held as hostages."
RIA said the evacuation of civilians and entrance of humanitarian aid were due to start on Friday morning.
ALEPPO "JUST PROMISE" ASSAULT
Syria's nearly 3-year conflict began as peaceful protests against four decades of Assad family rule and devolved into an armed insurgency after a fierce security crackdown.
Now the major Arab state is in a full-scale civil war that has killed more than 130,000 people and forced over 6 million - nearly a third of the population - to flee their homes.
In Aleppo, the Islamic Front, Syria's largest Sunni Islamist rebel alliance, joined forces with the Nusra Front, an al Qaeda franchise in Syria, to launch an assault dubbed "The just promise approaches", a reference to a Koranic verse about Judgment Day.
President Bashar al-Assad's forces recently mounted a series of attacks on Aleppo city, once Syria's business hub, using barrel bombs - oil drums or cylinders packed with explosives and metal fragments, dropped out of helicopters.
They are a particularly indiscriminate weapon activists say is being used to push out civilians as the army tries to seize the initiative on the long-stalemated Aleppo battlefront.
"All military forces in their bases should head to the front lines, otherwise they will be questioned and held accountable," a joint rebel statement said.
It warned residents near checkpoints and bases held by Syrian government forces to leave in the next 24 hours, saying the areas would be the insurgents' main targets.
Forces loyal to Assad have been making small gains on rebel-held parts of Syria's second city, advances which many opposition sources blame on weeks of rebel infighting that has killed more than 2,300 combatants.
The Islamic Front and some of its secular rebel allies are trying to oust an al Qaeda splinter group, the Islamic State of Iraq and the Levant, with whom they have ideological and territorial disputes.
Since government forces unleashed the barrel-bombing campaign on rebel-held Aleppo last week, residents have been leaving in droves to seek refuge in government-held parts of the divided city.
Others have fled to Turkey, where many have been held up at the border crossing as camps near Aleppo faced overcrowding.
The Syrian Observatory for Human Rights said Nusra Front fighters and the Islamist group Ahrar al-Sham had taken over a large part of Aleppo prison, freeing hundreds of prisoners and killing or wounding dozens of members of the security forces.
The Britain-based Observatory said the offensive against the prison was launched on Thursday by an Ahrar al-Sham suicide bomber, who blew himself up by the prison walls.
Government jets and artillery bombarded the area around the jail, which the Observatory said houses up to 3,000 prisoners and which has been the scene of repeated rebel attacks. (Additional reporting by Gabriela Baczynka in Moscow; Editing by Peter Graff)