GUWAHATI, India (AP) — At least nine workers are trapped inside a coal mine in India’s northeastern Assam state, officials said Tuesday, as authorities summoned the army to help in the rescue operation.

The miners were trapped on Monday morning in the Umrangso area in Dimapur Hasao district, some 125 miles (200 kilometers) south of the state capital, Guwahati.

The workers are “feared trapped 300 feet below the ground after water gushed in from a nearby unused mine. We are mobilizing resources to rescue them,” said Kaushik Rai, a local government minister who is monitoring the rescue at the site.

Authorities brought army soldiers and a national disaster management team to the area to assist in the ongoing operation.

Workers at the site said over a dozen miners had been trapped inside the mine, which has bare minimum safety measures, and that some miners managed to escape as water from a nearby unused mine began filling the mine.

In India’s east and northeast, workers extract coal in hazardous conditions in small “rat hole” mines that are rampant in the hilly areas. During the extraction, the coal is placed in boxes that are hoisted to the surface with pulleys.

Accidents in illegal mining are frequent and the livelihoods of those who do such mining depend on the illegal sale of coal.