Syrian forces mass outside rebel city

Syrian tanks and troops have massed outside the resistance stronghold of Homs for a possible ground assault that one activist warned could unleash a new round of fierce and bloody urban combat even as the Red Cross tried to broker a ceasefire to allow emergency aid in.

A flood of military reinforcements has been a prelude to previous offensives by President Bashar al-Assad's regime, which has tried to use its overwhelming firepower to crush an opposition that has been bolstered by defecting soldiers and hardened by 11 months of street battles.

"The human loss is going to be huge if they retake Baba Amr," said Rami Abdul-Rahman, who heads the Britain-based activist group Syrian Observatory for Human Rights.