Two people were killed in Seattle Wednesday and others were wounded after a gunman tried to carjack two vehicles, fatally shooting one driver, opened fire on a bus and killed another driver in a head-on collision before being arrested, police said.

Police said the violence that unfolded at around 4:05 p.m. in the north end of the city appears to be a random act, but cautioned that the investigation is ongoing.

Seattle Deputy Police Chief Marc Garth Green said "we only believe that this is a one lone suspect involved in this random, senseless act" and that "we're outraged at what this suspect did."

The suspect, who was taken to a hospital, was not immediately identified, but police said he lives in the area and fire officials said he was about 33 years old. Two of the wounded were described by police as being in critical condition.

Police said they don't know why the suspect went outside with a gun and attempted to carjack a woman and shot and wounded her, and then opened fire on a bus, striking and wounding the bus driver.

The suspect then carjacked a second vehicle, fatally shooting the driver, and fled in the car pursued by officers before crashing head-on with another car, killing that driver.

Police said the suspect was arrested after a brief standoff and suffered non-life threatening injuries.

Seattle Fire Chief Harold Scoggins said one of the wounded, a 57-year-old woman, was in critical condition. The bus driver also was taken to a hospital, he said.

A 50-year-old man was shot and pronounced dead at the scene, and a 70-year-old man died after the car crash, Scoggins said.

King County Metro tweeted that none of the 12 passengers on the bus were injured. Police said that after the gunman shot at the bus and wounded the driver, the bus driver moved it to a safe location.

The bus driver was hit in the torso but was able to walk to a gurney to be taken to a hospital, said Kenneth Price, president of Amalgamated Transit Union Local 587.

Seattle Mayor Jenny Durkan tweeted, "This is a tragedy for the Lake City community & all of Seattle.” She said she was grieving with the loved ones of those who were killed and extended her support to the injured, praising the bus driver who she said saved lives.

Washington Gov. Jay Inslee tweeted that he and his wife, Trudi, "are pulling for those injured, grieving for those who were killed, and appreciating the bravery of all who responded and took action to stop the shooter."