A water main break forced Scarborough police to close a section of Route 1 between Hillcrest Avenue and Pleasant Hill Road for at least 11 hours Thursday.

Portland Water District reported the water main break around 12:45 in a tweet. The road remained closed late Thursday night.

“The road will be reopened at some point tonight, at least one lane,” Michelle Clements, a spokeswoman for the water district, said late Thursday in an email.

Clements said motorists should avoid the area.

Clements said customers’ water service was affected, but was expected to be restored by midnight.