A man who robbed a bank Wednesday morning in Cologne is suspected in a Feb. 17 bank robbery in Orono and possibly as many as four others, the FBI said.

A masked man waited in the foyer of Kline Branch Bank and surprised an employee when she arrived to open the office for business, the FBI said.

He threatened her with a knife and demanded that she bring him to the vault. He showed a gun and said he would shoot her if she didn't cooperate, the FBI said.

The robber took an undisclosed amount of money and fled on foot.

Based on suspect descriptions and robbery methods, investigators are "fairly certain" that the suspect also robbed the First National Bank of the Lakes branch in Orono on Feb. 17, said Minneapolis FBI spokesman Steve Warfield.

He also may be linked to three or four other metro-area bank robberies in the past two months, he said.

The suspect in the Cologne robbery was described as about 6 feet tall, 200 pounds, in his late 30s or early 40s. He wore a tan- or wheat-colored coat, black pants, gloves and a black mask, the FBI said.