A suspected explosive device blocks Interstate 90 on Mercer Island

The Washington State Patrol closed Interstate 90 in both directions on Mercer Island Saturday afternoon after a suspected explosive device was thrown from a vehicle.

Bellevue police officers arrested two people from the car.

They began following a black sedan within Bellevue city limits when the driver sped off westbound on I-90.

State Trooper Rick Johnson reported the vehicle stopped near Island Crest Way and the driver appeared to throw an explosive device.

Bellevue officials requested assistance from the Washington State Patrol.

A State Patrol bomb technician team was dispatched to the scene.

Traffic on I-90 came to a standstill after police said someone appeared to throw an explosive device from a car during a traffic stop on Mercer Island. (Photo: WA Department of Transportation)

The closure brought traffic in both directions on the highway to a standstill.

I-90 was closed westbound on Bellevue Way SE

Police closed the eastbound lanes at 76th Avenue SE

Traffic on I-90 eastbound came to a standstill as Mercer Island police responded to an explosive device thrown from a vehicle near Island Crest Way. (Photo: WA Department of Transportation)

The closure worsened an already difficult weekend for Eastside drivers. Due to construction work, Bridge 520 is also closed all day on Saturdays and Sundays.