Two young siblings who disappeared from the front yard of their Jacksonville home over the weekend have been found, authorities said Tuesday.

Braxton Williams, 6, and Bri'ya Williams, 5, were last seen at about 11:30 a.m. Sunday outside their home in the Paradise Valley mobile park, the Jacksonville Sheriff's Office said.

"Great News! The Florida AMBER Alert for Braxton and Bri'ya Williams of Jacksonville has been resolved," the Florida Department of Law Enforcement announced late Tuesday afternoon. "The children are safe. Thank you for sharing!"

Jacksonville Sheriff Mike Williams said the children appeared to have wandered off and took shelter in a dilapidated pumphouse about 400 yards from their home at about 3:30 p.m Tuesday. Authorities were still trying to get more details from the children.

"As far as their condition goes, they're lively and talkative," the sheriff said. "They asked for a cheese pizza that we quickly delivered to them."

Braxton, who authorities said is "on the Autism Spectrum but will communicate with others," and Bri'ya were being treated for dehydration and minor injuries Tuesday.

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Hours earlier, T.K. Waters, chief of investigations for the sheriff's office, told reporters that investigators received information that a four-door older-model white car playing "loud children's music" had been seen in the neighborhood.

Detectives searched more than 430 houses in the community and more than 20 bodies of water, Waters said. Authorities also spoke to Braxton's and Bri'ya's parents, who were fully cooperative, he said.

Bryan Williams, the children's father, told NBC News that he had been setting up for a barbecue outside the home when he went inside for a minute or two. When he went back outside, Braxton and Bri'ya were gone, he said.

"I've been doing this for the last three years," he said, calling it a "normal" day.

Bryan Williams said the children's mother was also in the home at the time. He called police after he searched for the children but couldn't find them.