Doctors in northern India say they've surgically removed 40 knives from the stomach of a man who had swallowed them over the past two months.

The 42-year-old man is recovering in a hospital in Punjab state after undergoing surgery Friday in which doctors removed the knives — some folded and some with exposed blades up to 18 centimeters (7 inches) long.

Jatinder Malhotra, a doctor who was present during the five-hour operation, said Tuesday that the man, who works as a police constable, was apparently suffering from a psychiatric disorder and is now being counseled. He said the man could not explain why he swallowed the knives.

Malhotra said he had never before heard of a case of a person swallowing knives.