At least 15 people died and 26 others were injured after a liquid ammonia leak at a refrigeration unit in Shanghai on Saturday, local authorities said.

The accident took place at about 11 a.m. at the refrigeration unit in Baoshan District, the municipal government announced in a posting via its official account on Sina Weibo.

Among the injured, six are in critical condition.

Pictures uploaded to Sina Weibo show emergency response vehicles near the refrigeration unit