Midland City, Alabama - A gunman holding a five-year-old boy hostage in an underground bunker in rural Alabama was killed on Monday and the child was plucked to safety without injury, a local law enforcement official said.

“It's all over,” said the official, who asked not to be identified by name because he had not been authorised to discuss the operation that led to the successful rescue of the child.

“The boy is okay,” he said.

The rescue of the boy came on the seventh day of a standoff in a rural corner of south-east Alabama involving a suspect identified as 65-year-old Jimmy Lee Dykes, a retired trucker and Vietnam veteran.

Dykes seized the boy last Tuesday after boarding a school bus near his home and killing its driver with four shots from a 9mm handgun, local sheriff's department officials said.

The law enforcement source said a stun or flash grenade was detonated as part of the operation to free the boy, but further details were not immediately available.

The drama in Midland City, Alabama, came amid heightened concerns about gun violence and school safety across the United States after the December shooting deaths of 20 children and six adults at a Connecticut elementary school. - Reuters