OMAHA, NEB. -- At least seven people were taken to hospitals after an Omaha airport rally for U.S. President Donald Trump that drew thousands, many of whom were left stranded miles from their parked cars in freezing weather.

Omaha police said in a written statement that first responders dealt with 30 people for medical reasons throughout the day, and seven were taken to hospitals. Police-monitoring sites on social media reported that some people suffered adverse effects from temperatures hovering around 30 degrees as they waited for shuttle buses or tried to walk to their cars more than two miles away following the rally.

“Many people underestimated the distance from the event back to the parking lot on foot,” Officer Michael Pecha, spokesman for Omaha police, said in the statement.

Most of the thousands who attended the Tuesday night rally at Omaha's Eppley Airfield parked in remote lots and were shuttled to the event in buses. Police said 40 buses were used to shuttle 25,000 people over a 10-hour period, starting at 10 a.m., to the event site, although an undisclosed number left before the rally ended, police said.

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Traffic became snarled, and awaiting buses - which can hold about 50 riders each - were overwhelmed when crowds left the event around 9 p.m., police said. Additional buses were called in to try to get people to their cars.

Police said the last of the rally goers were able to leave around midnight.

Trump deputy national press secretary Samantha Zager said in a statement that the 40 shuttle buses the event deployed was twice the number usually deployed at Trump campaign rallies. But “local road closures and resulting congestion caused delays,” she said.

“At the guest departure location, we had tents, heaters, generators, hot cocoa, and handwarmers available for guests,” Zager said. “We always strive to provide the best guest experience at our events and we care about their safety.”

Democratic presidential nominee Joe Biden on Wednesday used the image of Omaha supporters left in the cold after the rally to criticize Trump's handling of the coronavirus pandemic.

“It's an image that captured President Trump's whole approach to this crisis,” Biden said.