“It happened at a place where it should never have. There’s no other reason but because those bad guys are still there,” Prayut said. “We have to get rid of these bad people and it’s time for us to get in hands together.”

Meanwhile, Deputy Defence Minister General Udomdej Sitabutr said that security officers were probing a threatening letter, claimed to be issued by the Barisan Revolusi Nasional movement, following Prayut’s order to accelerate investigation into the case.

Security has been tightened at other hospitals, Udomdej said.

“There have been threats following bombings in front of the National Theatre and the Government Lottery Office,” he said. “But we never thought that it would ever happen at a place like a hospital.”