PALGHAR: A fire broke out at the ancient Vasai Fort in Maharashtra's Palghar district on Monday night, an official said.
No casualty was reported and the structure also did not suffer any damage, he said.
The blaze erupted around 9 pm when some drug addicts were sitting in the fort compound.
One of them apparently threw a burning cigarette on the dry grass which caught fire.
The blaze then quickly spread in parts of the premises, a fire official said on Tuesday.
"There was no casualty. Some trees in the premises were destroyed, but the structure was not damaged," he said.
Fire brigade officials rushed to the spot and managed to douse the flames after about an hour, he added.
The fort was built in 1184 and is protected by the Archaeological Survey of India.
It is a major tourist attraction in the region for its Indo-Portuguese history.