The northbound lanes of Francis Scott Key Bridge were closed to morning commuters Friday as emergency crews deal with two accidents on the outer loop of the bridge.

Maryland Transportation Authority Police said two passenger vehicles collided on the bridge, and a tractor-trailer jackknifed while trying to avoid hitting them. Sgt. Jonathan Green, a spokesman for the transportation police, said the truck's size — a tractor pulling two trailers — the number of vehicles involved and the morning's light snow were complicating the investigation and clean-up process.

"For traffic, it's not a good scenario," he said. "We're lucky that there are no injuries."

Green said two towing companies were working to remove the vehicles. Traffic at the bridge's south base was being diverted to alternate routes, he added. In the immediate aftermath of the accident, both the southbound and northbound lanes of the bridge were closed, but police said as of about 8 a.m., only the northbound lanes were still shut to traffic.

"Everything that can be done is being done in terms of resources and detours," Green said. "Obviously we want to get this cleared."

jtorbati@baltsun.com