By Brendan O’Brien

(Reuters) – Authorities in southwest Washington were investigating on Thursday fires at two churches they believe were deliberately lit over the past two days and put places of worship in the area on high alert, police said.

The suspicious fires occurred at the First Congregational United Church of Christ in Vancouver, Washington, early Wednesday morning and at the Liberty Bible Church of the Nazarene on Thursday morning, the Clark County Sheriff’s Office said in a statement.

Authorities “are investigating these two incidents as intentional acts of arson,” the sheriff’s office said.

The Clark County Fire Department said authorities had yet to determine whether the two acts of suspected arson were committed by the same person.

Sheriff Chuck Atkins “is asking that all churches, synagogues, mosques, and other houses of worship, remain vigilant,” the sheriff’s department said.

Washington state media reported that the fire at the First Congregational United Church of Christ caused $2 million in damage. The fire at the Liberty Bible Church of the Nazarene was set when an object was thrown through a window and was quickly doused by the church’s sprinkler system, media reported.

No possible motive was known yet, the sheriff said.

Vancouver, Washington, is a community of 160,000 people about 10 miles (15 km) north of Portland, Oregon.

(Reporting by Brendan O’Brien in Milwaukee; Editing by Paul Tait)