SALEM, Ore. - Authorities arrested someone in the Salem area Sunday evening in connection with a bomb blast that killed two police officers at a Woodburn bank Friday and critically injured a third.

Investigators were withholding the identity of the person arrested at the request of the Marion County District Attorney's Office. The person's name, age and charges were not expected to be released until Monday afternoon.

It was not immediately clear whether the person arrested was the same person identified earlier Sunday as a "person of interest" in the case.

The arrest was made in the Salem area, but investigators would not be more specific.

"We know there is still a lot of hard work ahead of us, but this development will help bring relief to the local community and the officers' families," said Marion County Sheriff Russ Isham in a news release.

Woodburn police Capt. Tom Tennant and Oregon State Police Senior Trooper William Hakim were killed in the blast at the West Coast Bank on Friday.

Woodburn Police Chief Scott Russell was critically injured, but authorities said Sunday he was in stable condition at Oregon Health and Science University. A bank employee was also injured in the blast but was treated at a hospital.

Investigators said Sunday that cell phones might have been used in the bomb blast.

Cell phones and items that might have been used to make the bomb were bought in Bend last month, Isham said. The man identified as a "person of interest" might have taken actions "in furtherance of his plan" on Thursday and Friday in Salem and Woodburn, the sheriff said.

Authorities would not elaborate on how cell phones might have been used. Bombers often use cell phone signals to remotely detonate explosives.

Lt. Sheila Lorance of the Marion County Sheriff's Office, the lead agency in the case, did not have an explanation Sunday for why the officers who ended up dead or wounded took the bomb into the bank after it was found outside.

A West Coast Bank branch manager found the device Friday after a call about a bomb threat to a nearby Wells Fargo bank branch that turned up a harmless device.

Robert Sznewajs, the CEO of West Coast Bank, said Sunday that the bank planned to establish a fund for the families of the law enforcement officers.

Sznewajs said that all records and money kept at the branch were secure, and that it would reopen as soon as possible.

- The Associated Press contributed to this report