A container ship crashed into a major bridge in Baltimore early on Tuesday, causing it to snap in several places and plunge into the river below.

Two people were pulled from the water, according to Baltimore fire chief James Wallace.

One person was said to be in a serious condition while the second person was not seriously injured.

Mr Wallace said authorities “may be looking for upwards of seven people” but he said that number could change.

The vessel appears to have hit one of the supports of the Francis Scott Key Bridge, causing the roadway to break apart in several places and plunge into the water.

The ship caught fire and thick, black smoke billowed out of it.

“This is a dire emergency,” Kevin Cartwright, director of communications for the Baltimore Fire Department, told The Associated Press.

Though he said it was too early to know how many people were affected, he called the collapse a “developing mass casualty event”.

Emergency responders were searching for at least seven people believed to be in the water, Mr Cartwright said.

The Volunteer Firefighters from @jmvfc8, the Volunteer Swift Water Team and the @HarfordCoDES Special Operations Team are assisting the Unified Command at the Baltimore Francis Scott Key Bridge collapse. pic.twitter.com/ipoTR2HljY

— Harford Co., MD Fire & EMS (@HarforCoFireEMS) March 26, 2024

“Our focus right now is trying to rescue and recover these people.”

He added that some cargo appeared to be dangling from the bridge.

Maryland Governor Wes Moore declared a state of emergency and said he was working to get federal resources deployed.

The FBI was also on the scene.

Agencies reported receiving emergency calls around 1.30am reporting a vessel travelling outbound from Baltimore that had struck a column on the bridge, causing it to collapse.

Several vehicles were on the bridge at the time, including one the size of a tractor-trailer truck.

The temperature in the river was around 8 degrees Celsius in the early hours of Tuesday, according to the National Oceanic and Atmospheric Administration.

I have declared a State of Emergency here in Maryland and we are working with an interagency team to quickly deploy federal resources from the Biden Administration.

— Governor Wes Moore (@GovWesMoore) March 26, 2024

From a vantage point near the entrance to the bridge, jagged remnants of its steel frame were visible protruding from the water, with the on-ramp ending abruptly where the span once began.

Synergy Marine Group — which owns and manages the ship called the Dali — confirmed the vessel hit a pillar of the bridge at about 1:30am while it was in control of two pilots.

It said all crew members, including the pilots, were accounted for and there were no reports of any injuries.

I’m aware of and en route to the incident at the Key Bridge. I have been in contact with @BaltimoreFire Chief Wallace, @GovWesMoore @JohnnyOJr, and @AACoExec. Emergency personnel are on scene, and efforts are underway.

— Brandon M. Scott (@MayorBMScott) March 26, 2024

Mayor Brandon M Scott and Baltimore County Executive Johnny Olszewski Jr posted that emergency personnel were responding and rescue efforts were underway.

The Maryland Transportation Authority said: “All lanes closed both directions for incident on I-695 Key Bridge. Traffic is being detoured.”

The bridge, which opened in 1977, spans the Patapsco River, a vital artery that along with the Port of Baltimore is a hub for shipping on the East Coast. It is named after the writer of The Star-Spangled Banner, the US national anthem.