Fierce fighting between government troops and rebel forces is being reported in the Syrian city of Aleppo, amid concern among Western governments about reprisals against the civilian population of the country’s second city.

Troops backed by tanks and helicopter gunships, which had been massing for the past two days, moved on southwestern districts of the commercial hub, where rebel fighters have concentrated their forces lately.

Artillery pounded Salaheddin and other rebel neighbourhoods from early this morning, as ground troops made their advance.

Pro-government media had warned that the “mother of all battles” loomed in Aleppo as the government moved to reassert its authority after recapturing rebels’ districts of the capital earlier in the week.