The Boeing 757 made a safe emergency landing in Denver at around 11.35am on Thursday “after the crew declared an emergency due to a cracked windshield”, the FAA spokesman said in a statement.

A Delta spokesman said in a statement that there had been a “maintenance issue mid-flight” but did not elaborate.

“Out of an abundance of caution, the flight crew diverted into Denver and the plane landed routinely. Our team worked quickly to accommodate customers on a new plane, and we sincerely apologise for the delay and inconvenience to their travel plans,” the Delta spokesman said.

A person who said he was a passenger on the flight posted a photo of the windshield to Twitter, which showed the glass shattered into tiny fragments but still held in place.

There were 198 people on the plane, according to KUTV, which said the passengers changed planes in Denver and resumed their journey to Ronald Reagan National Airport in Washington.

Passenger Rachel Wright told the TV station that someone came on the loudspeaker about 90 minutes into the flight to say the windshield had shattered and they would be landing in Denver in 10 minutes.

“I was sure I had misheard them, but I hadn’t,” Wright said.