Opposition fighters and troops loyal to the regime in Syria were last night understood to be engaged in heavy fighting in the besieged city of Homs.
The battle, news of which is impossible to verify since the electricity supply to the city has largely been cut, came after a Syrian government official said that district of Baba Amr, a rebel stronghold, would be "cleansed".
"The army has started combing the area building by building and house by house. Now the troops are searching every basement and tunnel for arms and terrorists. There remain only a few pockets of resistance," the unnamed official told the Associated Press.
The fighting would pitch the largely under-armed opposition against Bashar al-Assad's brother, Maher, and his feared 4th Armoured Division, which is understood to have been sent to Homs. "We have nothing to do but pray for them." Abu Yaser, a Homs-based activist, said.
Some activists said they feared an assault on a comparable scale to the 1982 attack on the neighbouring city of Hama in which at least 10,000 people were killed. "The only aim is to repeat the massacre of Hama," a Homs-based activist styling himself Abu Bakr told AFP.
As the people of Baba Amr prepared for the expected onslaught, the international community worked on a new draft resolution calling for an end to the violence and access for humanitarian aid. However, despite unusual consensus between western nations and Russia and China, UN aid chief Valerie Amos said yesterday she was "deeply disappointed" that Syria has refused to allow her to the visit the country, where she had hoped to assess the need for emergency relief in besieged towns.
Describing how Assad's troops and tanks had circled west into an area of woodland close to Homs' al-Bassel football stadium, an activist who called himself Abu Emad said that Free Syrian Army troops were now holed up in abandoned apartment blocks trying to repel the regime's forces.
"Nobody knows how many troops the regime is using," he said, speaking from a neighbourhood adjacent to Baba Amr. "We hear that a lot of reinforcements are coming between Damascus and Homs every day, but we don't know the exact numbers of soldiers or tanks.
"The Free Syrian Army cannot face tanks with Kalashnikovs, so they are hiding in the buildings waiting for them to come. The shelling and rockets is still happening. The attacks were even more massive today. They are animals."
By last night it appeared that despite the assault, regime fighters had not yet broken lines protecting Baba Amr. "They are surrounding the district, while clashes are concentrated in the neighbourhoods of Inshaat and Malaab," said Hadi Abdullah on the Al Jazeera English news channel. Inshaat and Malaab lie on the northern edge of Baba Amr.
Another activist calling himself Molham, who said he was in the eastern Karm Zeitoun district, denied reports that the Syrian army was mounting an offensive against Baba Amr.
Adding to the uncertainty, some activists accused the regime of talking up an attack on the area. Speaking to The Independent, one Homs resident said: "This is fake news from the regime. The Syrian army cannot access Baba Amr. They want to make everybody afraid of the Assad regime and want to make the Free Syria Army afraid."
Despite the increased fighting, the Spanish newspaper El Mundo confirmed that its correspondent Javier Espinosa had arrived safely in Lebanon a day after the Sunday Times photographer Paul Conroy was also rescued.
Two Western journalists are believed to be in Baba Amr. Edith Bouvier of Le Figaro and Paris-based freelancer William Daniels have been trapped there since the attack that killed the Sunday Times reporter Marie Colvin and French photographer Remi Ochlik last week.