ROME - Two Air Force tornado jets collided in midair and crashed into wooded hills while on a training mission in central Italy, local authorities said on Tuesday.

The crashing happened near the town of Ascoli Piceno, in Marche region, setting off widespread fires in an area of wooded hills. No ground injuries have been reported.

The two pilots and two navigators of the aircraft were reported to be missing after ejecting before they crashed, according to the Italian Air Force.

"We are checking the dynamics of the accident," a spokesman of the Air Force told Sky television. "We had a confirmation of the radio signal that activated the seats' ejection," he said.

Several planes and search-and-rescue teams were checking a wide zone surrounding the crash site. They reportedly found a parachute later in the day but there was no trace of the four airmen.

The two jets were coming from the Ghedi air base in northern Italy. They were flying low, according to eyewitnesses, and were expected to return to the base after the training mission.

Firefighters were struggling to contain the raging forest fires that risked to reach the nearby villages, Ascoli Piceno Mayor Guido Castelli was quoted as saying by Rai state television.

Eyewitnesses quoted by la Repubblica newspaper said they saw the two jets "touching" in midair, then one of them burst into flames and both fell out of the sky.

"I was working at a computer in my home in Ascoli Piceno, when I heard a plane passing over me," a man told ANSA news agency.

"I looked out of the window and a few seconds later I saw another jet coming roughly from the opposite direction. The two aircraft collided and exploded," he added.

The collision's roar was reportedly heard up to 25 km away, while fragments and incendiary debris of the aircraft were described by local residents as falling "like confetti."