SALEM, Ore. -- Three schools were put into lockdown after a Blockbuster employee was robbed at gunpoint, police said.

It wasn't clear how many customers were in the store when a robber entered, pulled out a gun and robbed an employee, said Lt. Dave Okada of the Salem Police Department.

The employee gave the robber an undisclosed amount of money, which he put in a black bag, and the man left the store, Okada said.

The employee called 911 and police responded with a K-9 unit and began to search for the robber while three schools were put into lockout mode: Parish Middle School, Englewood Elementary School and North Salem High School.

Officers were unable to find the robber and think he may have used a car to escape, Okada said.

The schools were later released from lockout mode when the man couldn't be found, Okada said.

The robber is described as a white man in his 40s with a thin build. He was wearing a dark leather jacket, blue jeans and white tennis shoes.