Syrian rebels launched an offensive in the northern province of Aleppo on Thursday, as government airstrikes killed at least 11 people in an opposition-held neighborhood of the provincial capital, activists said.

For nearly two months, President Bashar Assad’s forces have waged a relentless and deadly aerial campaign against the city of Aleppo, which has allowed his troops to make modest inroads in recent weeks in rebel-controlled areas of the divided city. It has also fueled speculation that the government is laying the foundations for a large-scale attack to try to wrest back control of the neighborhoods it lost some 18 months ago.

In the past five days alone, airstrikes with so-called barrel bombs have killed at least 246 people, including 73 children, in Aleppo, the Britain-based Syrian Observatory for Human Rights said Thursday. The makeshift bombs — barrels or storage container packed with explosives, fuel and scrap metal — inflict massive damage upon impact. […]