The police said Saturday both were dead at the scene of the explosion the day before, but the police had delayed announcing the death of Senior Trooper William Hakim so his family could be notified.
No suspects are yet in custody, officials said Saturday.
"That person is dangerous and needs to be found as soon as possible," said Lt. Gregg Hastings, spokesman for the Oregon State Police.
The explosion occurred late Friday afternoon after police arrived at the West Coast Bank branch office to check a suspicious device.
Late Friday, police said a Woodburn police officer died from the explosion. On Saturday, the State Police said one of their bomb technicians had also died at the scene.
The dead were identified as Hakim and Woodburn police Capt. Tom Tennant, both 51.
Woodburn Police Chief Scott Russell, 46, was injured and in critical condition at a Portland hospital.
Police wouldn't discuss a possible motive for the bombing.
State police say the inside of the bank was extensively damaged, and a female employee was treated at Salem Hospital and released. Another bank employee was uninjured.
Hastings declined to describe the bomb in detail but indicated it was powerful.
A bank employee found the bomb in bushes outside the bank, and officers took it inside, when it exploded.
There was no explanation Saturday for their action.
"That we don't know," Hastings said when asked why the bomb had been taken inside.
Police sealed the area around the bank, and it remained closed Saturday. "There's no indication of further devices," Hastings said.
The explosion at 5:24 p.m. Friday followed a bomb threat call to a nearby Wells Fargo branch bank. The State Police said Saturday that investigators found "a suspicious object" that turned out to be harmless.
But the police said their investigation "led next door to the West Coast Bank," where the bomb was found.
Hastings said he didn't know of any grudges against the West Coast Bank.
Federal authorities said Saturday they were offering a $35,000 reward for information leading to an arrest and conviction in the case.
Anyone with information is being urged to call the ATF hotline at (800) 800-3855.