The country's terror alert for mass transit was raised to orange after coordinated explosions ripped through three London subway trains and a bus, killing at least 40 people. The attacks had the trademarks of the al-Qaida network, terrorism experts said.

There was no specific threat to transit operations in King County, Sheriff Sue Rahr said during a news conference at the Regional Command and Communication Center in Renton.

But police, sheriff's, fire and transportation officials were taking added precautions at transit facilities, she said, adding that that bomb-sniffing dogs from the sheriff's and police departments were making sweeps of Seattle's downtown bus tunnel.

Two sheriff's patrol cars were parked inside the tunnel during the morning commute and several vehicles were driving slowly up and down the tunnel. Officers said they regularly patrol the tunnel, but people waiting for buses said it was the first time they had ever seen any patrol cars driving where the buses usually go.

Bus riders who were aware of the London attacks said they had no effect on their morning commute. "I don't even live in fear no matter what," said Nicki Javurek, 19, who moved to Seattle from the Midwest about 10 months ago.

Dawn Deleon, 42, who was born in London and raised in New York City, said, "I can't let it affect my life because then terrorism wins."

She said increased security was a good idea but didn't want to see Prime Minister Tony Blair retaliate for the attacks in London. "He should send more support to support our troops from America," said Deleon, who is an American citizen.

She added, however, that it may be time to "leave well enough alone and bring our men home" from Iraq.

Jackie Sinar, 76, who has lived in Seattle most of her life, said she takes the bus every day and didn't think twice Thursday even after hearing the news from London.

"I just figure I'm going where I'm going and hope for the best," Sinar said.

The retired payroll clerk said Americans are more vulnerable today and she worried about the life her five grandchildren will have.

Seattle Police Chief Gil Kerlikowske also met with city Fire Chief Gregory Dean and other emergency officials to share information and coordinate plans.

Over the next few days, more police will be visible throughout Seattle, Assistant Police Chief Nick Metz said.

Police patrols were added at the city's downtown bus tunnel and bus drivers were told to increase inspections of their vehicles before going on the road, said Linda Thielke, Metro Transit spokeswoman. Passengers were asked to report anything suspicious to drivers or a police officer.

Officers also increased visibility and surveillance at rail and ferry stops as a precaution, Assistant Police Chief Jim Pugel said.

Gov. Christine Gregoire, who was in London last month on a trade mission, offered condolences to Londoners and gave assurances that similar attacks were not expected in America.

"I have been informed by authorities that at this time there we do not have any specific intelligence indicating that this type of attack is planned against the United States," Gregoire said.

She added that Gen. Tim Lowenberg, chief of the state National Guard and director of the state's Military Department, was monitoring developments and information coming from Homeland Security and Great Britain.

"I am confident that all reasonable precautions are being taken to protect the people of Washington," Gregoire said.