Syrian unrest: Army in control of Jisr al-Shughour
The Syrian army has taken control of the northern town of Jisr al-Shughour following what state media has described as heavy fighting.
A BBC reporter embedded with troops says clashes erupted after the army entered the town at dawn. Sources said three people had died.
The government said it was trying to restore order after 120 security personnel were killed last week.
Residents say they died after a mutiny and fighting between security forces.
The government operation sent hundreds more people fleeing towards the Turkish border, to join thousands who have already crossed.
BBC correspondents on the border say the number of those who have crossed is probably higher than the official figure of 5,050 given on Sunday afternoon by the UN's refugee agency, the UNHCR.
Witnesses said there might be as many as 10,000 sheltering in the area.
US officials say the crackdown has created a humanitarian crisis, and called for the International Committee of the Red Cross (ICRC) to be given access.
"No-one is aware of the real magnitude of the problem and this is a big issue, because it does not allow us to know the size of the problem and then to act accordingly," ICRC spokesman Hicham Hassan told the BBC.
On the Turkish side, two camps are already full of refugees and a third is filling up rapidly.
"The situation is grim. People were forced to flee with a few possessions. We are relying on the Turkish authorities for everything," Mohammed, one of those in the border area, told the BBC.
"No-one knows when it will be safe to return to our homes. When we return people expect to find their homes destroyed and bodies unburied."
Human rights activists and residents said troops began bombarding Jisr al-Shughour early on Sunday. They then began to move in from the east and south in a two-pronged attack with 200 military vehicles, they added.
Helicopter gunships were also seen hovering overhead.
The BBC Arabic correspondent accompanying the troops confirmed that there had been clashes after the advance began at dawn.
An Associated Press reporter meanwhile said he had seen two bodies at the National Hospital, which he said was damaged, with a burned-out ambulance outside.
State TV said there had been "heavy confrontations" between "army units and members of armed organisations taking up positions in the surroundings of Jisr al-Shughour and inside it".
"Members of the armed organisations were killed, large numbers of them arrested, and lethal weapons in their possession were seized."
The state news agency, Sana, said that after entering the town, army units had "cleansed the National Hospital of armed elements".
Later, state TV said troops had discovered a mass grave at the town's security headquarters, which it said had been overrun by "armed organisations" and where 82 security personnel had been "massacred".
One resident told Reuters: "Tanks came from the south after shelling randomly and sending volleys of machinegun fire all over the town."
Fadi, a witness living near Jisr al-Shughour, also told al-Jazeera that there had been shelling but that the town was empty.
"There is no-one in the city to clash with, but they are firing in case there are army defectors in the city," he said.
The army, he added, had "hit the post office and the military security headquarters in order to show them on state TV and claim that armed men blasted and destroyed them".
But, speaking to the BBC, an army general denied any shelling. The troops were only after those responsible for the killings of security personnel earlier this week, the general insisted.
The BBC's Jim Muir, in Beirut, says the largely deserted town seems to have been recaptured without much resistance.
Syria has prevented most foreign journalists from entering the country, making it difficult to independently verify reports from there.
A senior Western diplomat in Damascus told Reuters: "The official version is improbable. Most people had left Jisr al-Shughour after seeing the regime's scorched earth policy, shelling and the heavy use of armour."
On Saturday, witnesses described homes being bulldozed in nearby villages and crops and fields burnt and uprooted.
Violence has also been reported in surrounding areas, including the town of Maarat al-Numan, where armed men are said to have attacked the courthouse, police station and strategic fuel depot.
Meanwhile, there are continuing but unverifiable reports of army defections, with the latest saying an officer and 50 men had changed sides rather than fire on civilians in Jisr al-Shughour.
Protests against President Assad, who succeeded his father Hafez in 2000, began in mid-March and have spread across the country.
Rights groups say more than 1,200 people have been killed in the crackdown.