Seven Buddhist monks, including nationals from India, Russia, and Romania, died when a cable-operated rail cart overturned at the Na Uyana Aranya Senasanaya monastery in northwestern Sri Lanka.

Six others were injured, with four remaining in critical condition, police said.

The accident occurred Wednesday night at the forest monastery in Nikaweratiya, about 125 kilometers from Colombo.

Preliminary reports suggest the cable-driven cart lost control while descending an incline, though police are still investigating.

The cart ran alongside a steep stone staircase used to access the monastery’s higher grounds.

Na Uyana Aranya Senasanaya, home to more than 200 monks, is renowned for meditation retreats and spiritual training, India Today has reported.

Founded in the 3rd century BCE, it is one of Sri Lanka’s oldest surviving forest monasteries.