A father drowned and his two children remain missing following a riptide incident on a Sonoma County beach on Sunday.

The two children, a four-year-old and a seven-year-old, were reportedly playing near the water on Blind Beach in Jenner when a sneaker wave crashed into them and swept them out into the ocean on Sunday afternoon. The incident, as KPIX reports, happened around 2:30 p.m., and the children's father jumped into the water in an attempt to rescue them.

The father, identified as 40-year-old Michael Wyman of Petaluma, apparently reached one of the children and was trying to pull the child to shore when they were both swept out further by a rip current.

"They were both his kids — a 4-year-old and a 6-year-old — apparently he grabbed onto the 4-year-old and was trying to pull him in and apparently got swept out further," says Sonoma County Sheriff Lt. Michael Raasch, speaking to KPIX.

The mother, who was also present at the scene, was reportedly knocked down by a wave but managed to get herself out of the water alive, as KTVU reports, via Monte Rio Fire Protection District Chief Steve Baxman.

Both children were swept out to sea and have not been found despite extensive searching. Bystanders on the beach reportedly pulled the father into shore and attempts were made to perform CPR. But the father was pronounced dead at the beach at 3:05 p.m., per KTVU.

A High Surf Advisory remains in effect for Bay Area beaches through Tuesday, with waves as high as 24 feet.

"The waves are very treacherous, even very strong swimmers would have trouble getting out of the water," said Raasch to KPIX.

The search for the children continued Monday morning.

Update: The children were presumed dead and the search called off as of Monday afternoon.

Photo via Monte Rio Fire Protection District

*This post has been updated to correct the age of the older child, who was 7, and the father, who was 40, not 29 — and to add late-breaking identification of the father.