Cops believe that a man who molested a young girl in Queens Wednesday is responsible for a similar attack three hours earlier.

In the first attack, the suspect approached a 7-year-old girl on the stoop of her South Ozone Park home at about 2:45 p.m. and grabbed her buttocks, according to police.

The victim’s 12-year-old sister was on a nearby stoop and started screaming as the suspect fled.

Cops believe the creep struck again about three hours later when he approached another 7-year-old girl in the neighborhood after she left her family’s back yard to retrieve a ball.

He grabbed the girl’s buttocks, authorities said.

Cops described the suspect as a dark-skinned man in his 20s standing about 5 feet tall and weighing 160 pounds.