MOBILE, Alabama (Reuters) - An Alabama father confessed to throwing his four young children from a high-rise bridge into coastal waters after an argument with his wife, police said on Wednesday.

Lam Luong, 37, of Irvington, Alabama, was charged with four counts of murder and was being held in the Mobile County, Alabama, jail. He was scheduled for a bond hearing on Thursday.

Searchers in boats and helicopters were scouring 100 square miles of coastal Alabama waterways for the children, who ranged in age from four months to three years and were presumed dead.

Investigators said Luong first reported the children missing on Monday but later admitted he threw them from the 80-foot (24-metre) bridge connecting the Alabama mainland to Dauphin Island near Mobile following a dispute with his wife.

“We’re doing an extensive search,” said Sgt. Jerry Taylor of the Mobile County Sheriff’s Department.

Seven law enforcement agencies, including the U.S. Coast Guard, joined the search, which resumed at daybreak on Wednesday after being called off Tuesday night due to rough water and fog.

Divers were also involved in the search for the bodies of the children, along with boats using sonar.

Police identified the children as 4-month-old Danny Luong; Lindsey Luong, 1; Hannah Luong, 2; and 3-year-old Ryan Phan.

Local media, citing a law enforcement official, said Phan was not Luong’s biological child but the suspect had raised the boy from the time he was an infant.

Mobile County Sheriff Sam Cochran said authorities were confident the children would be found, but “we don’t believe the chance of someone being in the water here alive is very good,” the Mobile Press-Register reported on its web site.