A former South Korean coast guard chief was indicted Tuesday for allegedly bungling rescue operations at one of the country's deadliest maritime disasters, when more than 300 people were killed, most of them schoolchildren.

The 6,825-tonne Sewol capsized off the south coast in April 2014, and many of the students -- who were on a school trip -- obeyed orders to stay in their cabins as the vessel slowly sank.

The disaster triggered intense public fury when it emerged then-president Park Geun-hye was uncontactable for several hours as the disaster unfolded.

More than 300 people, mostly children, died in the Sewol ferry disaster
More than 300 people, mostly children, died in the Sewol ferry disaster AFP / JUNG YEON-JE

Kim Suk-kyoon, who led the coast guard at the time of the accident, was indicted on accusations of "professional negligence resulting in death" for failing to take necessary rescue action, said a prosecution representative.

He is the most senior official to face criminal trial over the sinking, but another 10 current and former coast guard officers were also indicted on the same charges.

The Sewol's captain Lee Joon-seok -- one of the first people to leave the sinking ship, abandoning hundreds of children trapped inside -- was convicted of negligence and murder in 2015 and sentenced to life in prison.

Other crew members were jailed for terms ranging from 18 months to 12 years.

Coast Guard