The Francis Scott Key Bridge in the US city of Baltimore collapsed after a ship collided with it, the Maryland Transportation Authority said early Tuesday.

“I-695 Key Bridge collapse due to ship strike,” the MTA posted on social media platform X, referring to the interstate highway. It urged drivers to avoid the route over the Patapsco River, which it called an “active scene”.

Earlier, the MTA had said interstate lanes in both directions were closed due to an “incident” on the bridge and that traffic was being redirected.

A police spokesperson from the Baltimore Police Department told NBC News that people were possibly in the river.

“I can confirm at 1:35 a.m., Baltimore City police were notified of a partial bridge collapse, with workers possibly in the water, at the Francis Scott Key Bridge,” Detective Niki Fennoy said in a statement.

Ship monitoring website Marine Traffic showed a Singapore-flagged container ship called the Dali stopped under the bridge early Tuesday.

Baltimore Mayor Brandon Scoot and Baltimore County Executive Johnny Olszewski Jr both said they were aware of the incident and that rescue efforts were underway.

“Please pray for those impacted,” Olszewski posted on X.