PEPPERELL -- Vandals have spray-painted the town's covered bridge on Groton Street twice since Monday, police said.

In a statement, Police Chief David Scott said officers responded to a emailed report that the bridge's wooden exterior was marked in black paint with dozens of symbols.

On Thursday, as the investigation was underway, a second incident occurred, police said.

More vandalism was found along the Nashua River Rail Trail, of which the bridge is part, police said.

The 100-foot-long expanse over the Nashua River is eight years old. It replaced a 1963 version in 2010. A bridge has been in that spot for more than 200 years.