Officers dock a boat that exploded, injuring six people at the Oak Grove Marina, near Edgewater, Maryland, on Monday..

Story highlights

NEW: Witness said man was throwing younger victims into the water

Six children were hospitalized, two went to burn unit

Boat had just refueled and captain was attempting to restart it

Marina is on South River in Maryland

CNN  — 

Six people were hospitalized after a boat exploded at a Maryland marina, an official with the Anne Arundel County Fire Department said Monday.

Six children, all of whom are 13 or younger, were injured, Lt. Jack Bell said.

“We saw that the dad was actually picking kids up and throwing them into the water, and people were just frantically scrambling to get off the boat,” Care Corradin told CNN affiliate WJZ.

Corradin said the people from the boat began to swim back to the dock.

“And there was a ton of smoke just billowing out the back, and the dad went back in and picked up all the life vests and he was throwing the life vests at the kids and the people in the water,” Corradin said.

Sgt. Brian Albert of the Maryland Natural Resources Police, which is leading the accident investigation, said two of the children were transported to the Johns Hopkins burn center. No one on the boat suffered life-threatening injuries, he said.

Bell said the boat got gas at the marina, and the 32-foot vessel, with nine people aboard, stalled when it left the dock just after noon. The blast happened when the captain tried to refire the engines.

The cause of the explosion at the Oak Grove Marina near Edgewater, Maryland, is unknown.

The marina is about 30 minutes east of Washington on the South River.