Although federal authorities have obtained a photograph of the man they believe robbed the Cambridge Savings Bank on Friday afternoon, they have not yet captured the suspect, officials said.

Federal Bureau of Investigation agents in Boston said they are interviewing eyewitnesses and have obtained descriptions and bank surveillance photographs of the masked man, who stole an undisclosed amount from the bank and fled on foot, said FBI spokesperson Peter S. Ginieres.

The bank itself has downplayed the incident, according to employees, some of whom said they were not even informed that it had taken place.

The suspect slid a note to the teller, "that it was a robbery, and he asked for money," said Cambridge Savings Bank spokesperson Alison A. Charello.

"The person indicated that [the package] was an explosive device. It had wires coming out of it," Ginieres said. "The bomb squad does not take any chances," he said, noting the bank was closed for three hours while the package was analyzed.

The Boston Bomb Squad determined the device was, in fact, not a bomb.

The masked robber, who escaped on foot from the bank on foot, was not apprehended.

"He just left the bank and by the time the police responded, the suspect had made his escape," Ginieres said. "We stress to the banks to take no action other than to agree to the demands of the robber...to not provoke the incident beyond where it is."

This bank robbery was not a solitary incident, according to both Cambridge Savings Bank and the FBI.

"[Harvard Square] has been the scene of a number of bank robberies and armored car heists," Ginieres said.

Bank of Boston, which is located next to Cambridge Savings Bank, was robbed in March 1995, and the Wainwright Bank was robbed last March.

Some Cambridge Savings Bank customers expressed suprise and doubt about the level of security in Harvard Square. Many were unaware that the robbery had even taken place.

"Obviously the security is not as tight as it should be," said Myniece Greenidge, a Cambridge Savings Bank customer.

"They usually don't put out a security guard until an hour before it closes. They don't make people aware [of robberies]. I didn't even know about it," he added.

A female bank employe, who spoke on condition of anonymity, said she wasn't told of the robbery. "I didn't know about it. That pretty much gives me a scare. Today was my first day there and I didn't hear anything about it."

Charello disagreed, saying the bank conveys such information "readily to our employees."