(REUTERS) – Syrian government forces and rebels fought battles north of Aleppo and in the city centre on Friday, a week into a Russian-backed offensive by the Syrian army to take the entire city, a war monitor and sources on both sides said.

There were conflicting accounts on the outcome of Friday’s fighting. The Syrian Observatory for Human Rights and a Syrian military source said government forces had captured territory north of the city and buildings in the city centre.

Rebel sources however denied any additional advances north of the city by government forces that seized the Handarat camp area north of Aleppo on Thursday. A rebel official said government forces had advanced in the Suleiman al-Halabi district of central Aleppo, but were then forced to withdraw.

The Syrian military and its allies launched a Russian-backed offensive one week ago aimed at capturing rebel-held districts of eastern Aleppo that are home to more than 250,000 people.

Aleppo has been divided into government and opposition sectors for four years.

A water station was bombed in the Suleiman al-Halabi district, dealing a further blow to a water system already badly damaged during the offensive. The Observatory blamed government forces. A Syrian military source, however, said rebels had blown it up.

The Observatory, a Britain-based war monitor, reported heavy bombardment by government forces and violent “back and forth” fighting in the Suleiman al-Halabi neighbourhood.

The Syrian military source said government forces captured several buildings in the area and were “continuing to chase the remnants of the terrorists fleeing them”.

The rebel official however said government forces had “advanced and then retreated”, losing “a number of dead”.

In the fighting north of Aleppo, the Observatory and a television station operated by Hezbollah said government forces had taken the Kindi Hospital area adjacent to the Handarat Palestinian refugee camp, a few kilometres (miles) from the city. Hezbollah is a Lebanese group fighting alongside the army.

But rebel sources denied that the government had captured the Kindi Hospital area, saying fighting was still going on.

A senior rebel official also said that government forces were shelling the rebel-held districts with artillery from a hilltop to the east of the city.