Two people are missing after two vehicles were swept off the road due to flooding caused by heavy rainfall in Oklahoma.

First responders are searching for two people who were in one of vehicles, a Jeep, after three other people were declared safe, in Moore, a city south of Oklahoma City.

The flooding comes as more than 30 million Americans are on alert for severe weather this Easter weekend, as several states in the Heartland have already been slammed with tornadoes, hail and damaging winds.

The two vehicles went off the road near Southeast 12th Street and S Eastern Avenue, the Moore Police Department told ABC News affiliate KOCO. Both vehicles were submerged in the water after being washed off a bridge, police said.

Police had earlier said they were working to assist "more than a dozen" motorists whose vehicles were stuck in high water.

"Multiple roads and neighbrhoods have water over the curbs," the department said on social media late on Saturday. "Stay home if at all possible."

This is a developing story. Please check back for updates.