A kidnapped toddler has been found wandering in the street miles from the Rhode Island home where his mother and another woman were found murdered in the US.

A patrolman in Providence spotted Isaiah Perez walking around the Chad Brown housing project by himself and apparently unharmed at around 8.15pm on Sunday.

An urgent search was launched for the two-year-old after two bodies were discovered at about 5.20am at a house in Johnston, a town of 30,000 residents just under 10 miles away.

Two men were arrested soon afterwards.

The boy was found in the state of Rhode Island

Malcolm Crowell, 22, was picked up in Fall River, Massachusetts and Daniel Rodriguez, aged 27 or 28, was arrested in the evening in Providence.

Both suspects are from Providence, but police gave no more details about their relationship to each other or to the victims.

It was unclear whether the boy's abductor was living in the home, was a guest or was uninvited, investigators said.

"What he was doing there, we have no idea," Johnston Deputy Police Chief Daniel Parrillo said earlier in the day.

When Isaiah first went missing, a nationwide Amber Alert was issued that identified him and also named Mr. Crowell as a suspect.