BATON ROUGE - Fire officials have ruled a Monday night house fire in Baton Rouge as arson.

According to the Baton Rouge Fire Department, the fire was reported around 9:24 p.m. on North 40th Street. The location is near Zion Street.

The fire started in the rear structure, which authorities believe is a vacant guest house, before spreading. Firefighters brought the fire under control just before 10 p.m. 

Neighbors described the property as a known area for "drug activity and vagrancy."

Anyone with information on the incident can call fire investigators at 225-345-1419.