Two aircraft collided Sunday at an airshow in northern Switzerland, media reports said, although further details were sketchy.
The accident occurred around 0930 GMT at Dittingen, the Swiss newspaper Tages-Anzeiger said on its website.
Local police were unable to provide any immediate details.
According to local newspaper Basellandschaftliche Zeitung, the aircraft were ultralights.
Also a pilot was in a critical condition in hospital on Sunday following a crash at the British airshow that killed seven people when his plane plunged into a busy road.
The historic Hawker Hunter military jet failed to pull up out of a loop at the Shoreham Airshow on the southeast English coast on Saturday, and hit several cars, creating a fireball that sent thick, black smoke billowing into the sky.
The pilot was airlifted to hospital where he is in a critical condition, Sussex Police said, though they were unable to say whether he had ejected from the plane.
“As far as we are aware all those who sadly lost their lives were on the road,” said the county force’s Superintendent Jane Derrick.
“At this time we are continuing to search… the area to ensure that we have identified all the casualties.
“It is possible that… we are going to find more bodies at the scene.”
Fourteen people sustained minor injuries, four of whom were taken to hospital.
Footage of the crash showed the jet attempting to perform a loop manoeuvre high in the air. The plane banked up steeply, turned over but did not complete the loop in time to avoid hitting the ground.
The crash happened at around 1:20 pm (1220 GMT) Saturday. The plane hit the A27, a major road that runs along England’s southeast coast.
Pictures from the scene showed police had cordoned off the four-lane dual carriageway road, with ambulances, fire crews and emergency service helicopters in attendance. Debris was visible across the road.
Eyewitness Chris Watkins told the BBC: “The Hunter came across the airfield, did a turn behind us and as it swooped down to do its run across the airfield it just ploughed straight in to the road and the trees.”
– ‘Not going to make this’ –
Stephen Jones, another witness, added: “He made a quick pass along the crowd line and pulled up into a loop and as he came out of it, I thought, ‘this is wrong, you’re too low, you’re not going to make this’.
“He just disappeared behind some low trees at the edge of the airfield and then there was a huge explosion.”
Gairo Gomez, who works nearby, said the whole building he was in shook.
“I saw the plane going down,” he added. “I heard a huge bang and the glass was shaking and the doors were banging, the whole building was shaking.”
A mainstay of Britain’s Royal Air Force in the 1950s and early 1960s, Hawker Hunter planes were used in campaigns such as the Suez Crisis and the Malayan Emergency.
Sunday’s second day of the airshow was cancelled.
Tim Loughton, the area’s representative in parliament, drove past the airshow entrance a few minutes before the crash and said cars were queuing to get in.
The MP said given the numbers attending the airshow, “thank God that the aircraft did not hit a larger crowd”.
“It’s horrific. It is a horrendous crash.”
Prime Minister David Cameron sent his condolences to the families of those who died.
A Downing Street spokesman said: “The prime minister sends his heartfelt condolences to the families of the people who were so tragically killed.
“The prime minister’s thoughts and prayers are with the families and friends of the victims.”
