Alabama ? An ammonia leak at a coastal Alabama chicken distribution plant sent more than 120 people to the hospital on Monday, including four patients in intensive care, and forced residents to hide in their homes while warning sirens blared.

At least 29 people were admitted to Mobile-area hospitals, including the four in intensive care. Injuries to most of those admitted were not believed to be life-threatening, and others were treated and released, mostly for breathing difficulties.

The leak also forced workers to evacuate one of BP PLC’s main staging areas for the oil spill cleanup. BP said dozens of cleanup workers from its Theodore site were among those taken to hospitals.