At least nine people were killed when a UPS cargo plane crashed while taking off from an airport in Louisville, Kentucky on Tuesday evening, the state's governor said.

Earlier, Andy Beshear said the plane's three crew members were likely to be among the dead after the freight plane exploded as it departed Louisville Muhammad Ali International Airport at around 17:15 local time (22:15 GMT).

At least 11 other people were injured when the plane crashed, sending thick plumes of black smoke into the sky.

Officials warned that people suffered "very significant" injuries in the incident and the death toll could rise.

Louisville Mayor Craig Greenberg said on Wednesday that the airport had reopened its runway so that flights were able to resume.

At least 16 different families have reported loved ones unaccounted for, according to Beshear.

Two workers at the auto business that was struck were still unaccounted for as of Tuesday evening, and it is not known how many customers were on the premises when the crash happened.

In a statement, UPS said three crew members were on board, adding "we have not confirmed any injuries/casualties".

A preliminary investigation is under way but officials have said it is too early to say what caused the crash.

Officials did note, though, that the massive blaze was due to the amount of fuel onboard the aircraft, which was beginning a journey of around 4,300 miles (6,920km) to Hawaii.

The aircraft was carrying 38,000 gallons (144,000 litres) of fuel when it crashed.

It has not been confirmed what cargo was on board, though officials have said the plane was not carrying anything that would create a heightened risk of contamination.

The explosion engulfed at least two nearby businesses, including a petroleum recycling company. A shelter-in-place order was initially issued for within five miles of the airport due to concerns of further explosions and air pollution, but was later reduced to just one mile.

All departing flights for Tuesday evening were cancelled, the airport said in a statement on X.

Louisville Fire Department chief Brian O'Neal said the amount of fuel spilled at the crash site made it a "very dangerous situation".

An order warning people to shelter in place was reduced from a five-mile radius from the airport to a one-mile radius as crews worked to contain the blaze on Tuesday night.

At a press conference, Beshear warned people not to go to the crash site.

"Anyone who has seen the images and the video knows how violent this crash is," he said.

"There are still dangerous things that are flammable, that are potentially explosive."

Beshear said he would not "speculate" as to what caused the incident, adding that the National Transportation Safety Bureau (NTSB) would be leading the investigation.

The NTSB's investigative team was due to arrive in Kentucky on Wednesday.

Louisville Metro Police Dept Chief Paul Humphrey said that the crash site will be "an ongoing active scene for the next several days".

He added: "We don't know how long it's going to take to render that scene safe for the investigation to take place."

The model of aircraft involved was a MD-11F triple-engine plane, which first entered service 34 years ago with Thai Airways as a passenger jet, but was transferred to UPS in 2006.

The aircraft was originally manufactured by McDonnell Douglas, which merged with Boeing in 1997.

In 2023, FedEx and UPS both announced plans to begin retiring their fleets of MD-11s over the next decade as part of plans to modernise their fleets.

In a statement, Boeing said it is "ready to support our customer" and that "our concern is for the safety and well-being of all those affected."

It added that it will offer technical assistance to the NTSB.

Louisville is home to UPS Worldport, a global hub for the delivery firm's air cargo operations and its largest package handling facility in the world.

During the press conference, Louisville Metro Council member Betsy Ruhe said that the city is a "UPS town", and that every resident would know somebody who works for company.

"They're all texting their friends, their family, trying to make sure everyone is safe," she said.

In a statement, UPS said it was "terribly saddened" by the incident and would be halting package sorting operations at Worldport on Tuesday night.

It added: "UPS is committed to the safety of our employees, and customers and the communities we serve. This is particularly true in Louisville, home to our airline and thousands of UPSers."