PHOENIX -- A man whose children were found walking alone on a freeway on-ramp during morning rush hour traffic Thursday said he felt "stupid" and "sick to his stomach" about what happened, court paperwork shows.

Carlton Anderson, 28, faces four counts of child abuse.

Police said a morning commuter found twins Justin and Hustin, age 3, on the southbound Interstate 17 on-ramp at Glendale Avenue and stayed with them until officers arrived.

Both children had dirty diapers and neither was wearing shoes, according to court paperwork. Hustin wore only the diaper.

Police located the children's home -- a unit in a nearby apartment complex -- and said they found two more children, ages 1 and 4, alone inside.

The apartment was dirty, with trash and broken beer bottles strewn about and only soda and bacon in the refrigerator, Detective Ruben Gonzales said.

"It looks like a half a loaf of bread that was inside the garbage -- that was pulled out, opened. You can see bread strewn about the apartment as if they were trying to eat that," Gonzales told KTAR-FM.

Officers went to a store and bought some breakfast food for the children to eat, he said.

Neighbors told police they had not seen the children's parents since 8 p.m. Wednesday night.

When Anderson returned to the apartment shortly after 8 a.m., police arrested him on suspicion of child neglect.

Anderson told investigators he left the apartment at 10 p.m. to pick up the children's mother from a bar, according to court paperwork. A neighbor told police Anderson asked her to watch the children, but she refused because he was "always" asking her to watch them, the paperwork shows.

When the children's mother refused to leave the bar, Anderson became upset and went drinking with a friend, then spent the night walking around and drinking, according to the paperwork.

Anderson admitted that the twins had left the apartment once before and were brought back by a neighbor who recognized them, court paperwork shows. He also said the children had been left alone before.

Anderson said he knew what he did was stupid and that he felt "sick to his stomach" about what happened, according to the paperwork.

Police were unable to locate the children's mother.

The children were given full medical exams and turned over to Child Protective Services.