CONCORD (CBS SF) — Police officers and Contra Costa County Fire Protection District crews responded to two structure fires Sunday evening, according to authorities.

The first, which police announced on Twitter at 5:10 p.m. Sunday, is at a house on Fallen Leaf Lane. Authorities ask residents to avoid the area as both directions of Concord Blvd. at Mariposa Ct. were closed for firefighting efforts.

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While police didn’t offer any details about the fire, they said Concord Blvd. had reopened shortly before 7 p.m.

The second is in the 2800 block of Concord Boulevard, police reported on Twitter at 5:48 p.m.

Police said that fire closed Concord Boulevard between Third Street and Parkside Drive.

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Concord Boulevard was reopened between those two streets by 6:35 p.m. Authorities are investigating the causes of both fires.