PHILADLEPHIA (CBS) -- Investigators suspect that an early morning house fire in Philadelphia was set intentionally, police said Saturday.

Police and firefighters responded to a home on the 4200 block of Passmore Street in Mayfair before 4 a.m. They found two women outside the house and they were taken to Frankford Torresdale Hospital, where they were listed in stable condition.

The blaze was extinguished in 20 minutes.

Later, a fire marshal ruled the fire was an arson.

Philadelphia police say a 40-year-old man is a suspect, and believe the fire was set after an argument.

The department's Northeast Detectives division is investigating.