BEIRUT — Syrian military helicopters dropped barrel bombs on a rebel-held neighborhood in the northern city of Aleppo on Monday, cleaving the fronts of apartment buildings and killing at least 27 people, activists said.

Government aircraft have pounded districts under opposition control in the divided city for months with the makeshift bombs— huge canisters packed with explosives and shrapnel that cause massive damage on impact. Activists say around 2,000 people have been killed in such attacks in Aleppo this year alone.

Monday’s air raids targeted the Sukkari neighborhood on the southern side of the city, the Britain-based Syrian Observatory for Human Rights and the Aleppo Media Center said.

The Observatory said at least 27 people were killed, while the Aleppo Media Center put the death toll at 30. Disparate figures are common in the immediate aftermath of large attacks.

Both activist groups said scores of wounded were rushed to makeshift hospitals in the city.

The Aleppo Media Center said the barrels struck near an aid distribution center, which in part explained the large number of casualties.

The Observatory said the second barrel struck as people were trying to help the wounded from the initial bombing.

An amateur video posted online shows people running through a rubble-filled street as sirens wail. Thick white dust hangs in the air. Four men carry a limp body out of a building in a red blanket. Nearby, a fruit stand with an umbrella and two plastic chairs sits undamaged.

Another video showed apartment buildings with their facades blown off.

The videos appear genuine and correspond to Associated Press reporting of the events depicted.

The Britain-based Observatory, which relies on a network of activists inside Syria for its information, also released a photograph it said showed the aftermath of the strike. It shows a heavily damaged building with one of the shops on the ground floor on fire. Debris and electric cables are scattered in the street.

Aleppo, Syria’s largest city, has been carved up into rebel- and government-controlled areas since opposition fighters launched an offensive in the country’s north in mid-2012.

Copyright 2014 The Associated Press.