WASHINGTON — Several cars at the back of a motorcade carrying Democratic vice presidential nominee Tim Walz crashed while heading from the airport to a campaign stop in Milwaukee on Monday, but Walz was unhurt.

President Biden called and spoke to Walz a short time later, as the president was traveling to a separate campaign stop in Pittsburgh with Vice President Kamala Harris. Harris’ campaign said that she also spoke with her running mate by phone after the crash and that he was not injured.

The Harris campaign said the crash involved cars near the rear of the motorcade. Walz, who is also the governor of Minnesota, was riding closer to the front.

It wasn’t immediately clear what caused the crash, which occurred shortly before 1 p.m. local time and caused some minor injuries.

The White House said that Harris was briefed on the collision and spoke with Walz to check on him and the staff. She’s expected to get updates throughout the day.

A member of the traveling pool staff, who was in a van carrying reporters, was injured and being treated by medics, according to a pool report from a reporter traveling in Walz’s motorcade, who wrote that passengers were “violently thrown forward, as our van slammed into the one in front of us and was hit from behind.”

The van carrying the reporters remained pulled over on the side of the road for several minutes afterward.

Some reporters had scrapes and bruises and one had a bloody nose. Another feared having suffered a concussion and was initially looking to be taken to urgent care – but eventually climbed aboard a new van to accompany the rest of the press to the event.

All who wanted to be checked out by paramedics were assessed, according to the pool report.

The crash occurred after Walz and his wife, Gwen, were greeted at the airport by Democratic Rep. Gwen Moore of Wisconsin. The trio embraced, chatted and posed for a photo before the motorcade began heading to the event.

Monday’s campaign stops marking Labor Day were Walz’s first aboard the Harris-Walz campaign charter aircraft. It bears decals of an American flag, the words Harris-Walz, and “A New Way Forward.”