BEIRUT ( AP) — Government troops heavily shelled rebellious districts in the resistance stronghold of Homs today, killing at least seven people and compounding fears of a new round of bloody urban combat in a country careening toward allout civil war.

Activists said the intense shelling of Baba Amr in Homs lasted a few hours but did not seem to be the start of a widely expected military offensive aimed at retaking rebel-held neighborhoods in the central region. One of the seven people killed in the shelling of Baba Amr was a child, according to the British-based Syrian Observatory for Human Rights, which relies on a network of activists on the ground.

An activist inside the city said the shelling started after repeated attempts by troops to storm the edges of Baba Amr.

“Government troops have been unable to advance because of stiff resistance from defectors inside,” he told The Associated Press on condition of anonymity, fearing government reprisals.

The military sent columns of tanks and other reinforcements toward Homs on Monday, activists said. A flood of military reinforcements has been a prelude to previous offensives by President Bashar Assad’s authoritarian 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.