Baltimore blast kills at least one; children trapped

The Baltimore Sun reported it was a natural gas explosion, citing fire officials, but said the exact cause remained unknown.

The Baltimore City Fire Department posted on twitter: "One adult woman deceased as BCFD continue to search for more".

Three patients, all in critical condition, were rescued by firefighters, the Baltimore Firefighters IAFF Local 734 wrote on Twitter.

"Several houses exploded. At least 5 people trapped, some children," the union said.

"Rescuers are communicating with one person still trapped. #BCFDSRO Special Rescue Operations Team is working to get to the person. One person has been pronounced dead on scene," the union said in a separate post.

Officials from Baltimore Gas and Electric Co and the Baltimore Office of Emergency Management were at the scene, the Baltimore Sun reported.

"We are on the scene and working closely with the fire department to make the situation safe," gas company spokesman Richard Yost told the Sun. "Crews are working to turn off gas to the buildings in the immediate area. Once the gas is off we can begin to safely assess the situation including inspections of BGE equipment."