Eleven people have died after a civilian aircraft carrying skydivers crashed in the town of Tomblaine in eastern France, local officials said.

The pilot and all 10 passengers were killed, including five instructors and five people who were preparing to skydive for the first time.

The plane, which was being used by a parachutist school, had taken off from Nancy-Essey airfield when it crashed suddenly at around 11:00 local time (10:00 BST).

The Paris prosecutor's office has launched an investigation into the cause of the incident, French Interior Minister Laurent Nuñez said.

Some of the victims' relatives saw the crash take place, as they had gathered at the airfield to watch the first-time tandem jumps, Nuñez added.

The mayor of the nearby city of Nancy, Mathieu Klein, said some of the victims had died "in full view of their loved ones".

Chaynesse Khirouni, president of the eastern department of Meurthe-et-Moselle, said those family members had suffered "considerable psychological trauma".

Nuñez said there was "very strong emotion" when he visited the crash site, as well as "great solidarity" for the families of the victims.

Medical and psychological support teams had arrived to care for relatives and other witnesses, he added.

The plane hit the ground near the edge of the airfield, close to a residential area and a shopping centre. Local officials say it narrowly missed the houses nearby.

"Give or take a few metres and the accident could have caused collateral casualties," said Yves Seguy, the prefect of Meurthe-et-Moselle.

He told French broadcaster BFM that the plane had fallen "almost vertically, in the immediate vicinity of a housing estate".

Half of the skydivers who died were nurses, the president of a local nursing organisation, Thierry Pechey, told BFM.

"They were colleagues who had decided to go on a first skydiving jump, no doubt to unwind, as we're going through a difficult time with the heatwave," he said.

The crash is the deadliest private plane accident in French history, excluding military and commercial flights, news agency AFP reports, citing the country's BEA aviation safety agency.

A witness, who declined to be identified, told Reuters he saw the plane veering off to the right as he was driving past.

"Something was clearly wrong," he said.

The man did not see the crash, due to an embankment by the side of the road, but he says he heard the sound.

When he arrived at the site, he tried to help extinguish the wreckage of the plane, which had caught fire.

"We saw right away that it was over, that they had all died instantly. There was no movement, and it was clear the impact had been too violent for there to be any survivors."

Tomblaine Mayor Hervé Feron said the plane had fallen from the sky "in a completely unexplained manner", adding that it was "too early to try to find explanations".

"Weather conditions might have played a role, or perhaps not at all, I really have no idea," he told BFM.

It was not immediately clear if the weather was a factor in the crash, and Nuñez has declined to speculate ahead of the official investigation.

Like much of Europe, France has been gripped by a searing heatwave in recent days. An amber weather warning for high temperatures was in place for Meurthe-et-Moselle on Sunday.