Fighting in the area around Aleppo has escalated dramatically over the past few days, and spiked to new highs Friday, with heavy Syrian airstrikes against the Nusra Front-held half of the city, killing at least 91 people, including dozens of civilian bystanders, and destroying some 40 buildings. 25 more were reported slain early Saturday.

Aid workers claimed the current strikes are the biggest yet seen in the city, which is really saying something since both sides have been pounding one another for months. The Syrian Civil Defense aid group reported several of their sites were hit in the course of the fight, knocking out many of their rescue vehicles.

Nusra Front commanders also reported some of their fighters had been hit in the campaign, saying that there are “martyrs under the rubble” in three different locations in the city.” The Syrian military had warned over the past two days that civilians should avoid areas around Nusra Front facilities.

Aleppo has already sustained massive damage over the course of the civil war, and today’s destruction just adds to the number of buildings left leveled, and likely to remain in ruins for the duration of the conflict, with no one really able to do any repairs.

Syrian forces have been reported to be preparing a full ground invasion of Aleppo, and are already advancing in the surrounding area.