Investigators suspect a fire that damaged part of a church in Portland was arson.

According to the Portland Press Herald, neighbors used buckets of water to try to douse the flames at Portland New Church on Stevens Avenue, which broke out early Sunday between 1 a.m. and 2 a.m.

Lorraine Kardash, the church’s pastor and building manager, tells the paper the fire appears to have been set where a Black Lives Matter sign had been hanging. She said investigators found the sign in bushes nearby.

The fire was mostly contained to the front of the building and a stairwell.

In a post on social media, church leadership said “We are saddened and angered by this hateful act.”

The church has scheduled a peace picnic for October 10th. Members of the community including police and firefighters will be invited to stand up for diversity, the church says.