The hunt for an arsonist has intensified as two more suspicious fires hit a downtown San Jose neighborhood that has seen a string of fires this week.

A fire captain says 11 of 13 fires that broke out in the area were intentionally set, including two that struck early Sunday.

KTVU-TV reports one was extinguished by residents before firefighters arrived, and a second one charred a storage trailer that was burned in a Wednesday blaze behind a Baptist church.

Firefighters say the arsonist appeared to be growing bolder by apparently returning to the scene of the crime.

Authorities have released a sketch of the suspect and offered up to $10,000 for information leading to his arrest and conviction.