FRISCO The Frisco Fire Department said a house fire early Sunday morning is suspicious.
It is one of four fires on the city's west side in recent months.
Three are considered arson two of those were at houses that were under construction.
Sunday's fire in the 700 block of Burr Oak Drive was at a vacant house that's up for sale.
A 911 call came in around 4 a.m. Sunday from the Grayhawk subdivision. Firefighters arrived to find flames shooting from the back of the residence.
State and local fire investigators were there Sunday afternoon trying to determine if this latest fire is related to the string of arson cases.
Fire officials said they are marshaling additional resources to find out who is setting the fires.