BBC - Eleven skydivers and one pilot have been killed in a plane crash in the US state of Missouri, officials have said.
The airplane, which was leased by a skydiving company, took off around 11:20 local time (16:20 GMT) on Sunday, according to a Bates County Emergency Management spokesperson.
After failing to gain altitude, it made a sharp left turn and crashed about 200 yards away from Butler Memorial Airport, the spokesperson told the BBC. All 12 people on board died, he said.
"We are treating that... as a mass casualty," Bates County Sheriff Chad Anderson said during an afternoon news conference.
The sheriff said the plane had not been a commercial airliner, and rather "a local airplane that took off from our local airport".
The Federal Aviation Administration (FAA) said the plane was a Pacific Aerospace P750 and crashed while departing the airport.
"Air traffic services were not being provided at the time," the FAA said. A spokesperson explained that the plane was not required to be in communication due to the type of air space it was flying in.
Local media reported that first responders checked the area to see if any of the skydivers had jumped from the plane before the crash.
Some family members of the deceased witnessed the incident, the sheriff said.
Authorities have not shared information on the identities of the victims.
The city of Butler is about 50 miles south of the Kansas City metropolitan area.
The National Transportation Safety Board (NTSB) is leading the investigation into the crash, the FAA said.
The BBC has contacted the NTSB.