A former soldier is wanted on suspicion of murder after his three young daughters were found dead at a campsite in central Washington state.

Authorities asked the public on Tuesday for help finding Travis Decker, 32, who is wanted for three counts of murder and kidnapping, according to police in Wenatchee, about 100 miles (160 kilometers) east of Seattle.

Police said it was unknown whether Mr Decker, a former army soldier with “extensive training”, was armed.

On Friday, the mother of Paityn, nine, Evelyn, eight, and Olivia Decker, five, reported that their father did not return them after a planned visit, police said.

Over the weekend, authorities looked for the children and for Mr Decker, who was believed to be living out of a white 2017 GMC Sierra pick-up truck with Washington plates.