Experts investigating the site of a cargo plane crash in Greece say they have found no evidence of dangerous substances but that a lot of widespread ordnance remains, while Serbia’s defence minister confirmed that all eight crew members had died in the incident.

The An-12 cargo plane from Serbia, flown by a Ukrainian aviation crew, crashed into fields between two northern Greek villages late on Saturday.

Its fuselage dragged on the ground for 170 meters (nearly 190 yards) before it disintegrated, authorities said. Locals reported seeing a fireball and hearing explosions for two hours after the crash.

Serbian defence minister Nebojsa Stefanovic told a news conference on Sunday that the plane was carrying 11.5 tons of Serbian-made mortar ammunition to Bangladesh, which was the buyer. It had taken off from the Serbian city of Nis and had been due to make a stopover in Amman, Jordan.

The Greek army’s Special Joint Nuclear, Biological and Chemical Defence Unit cleared two paths for Fire Service forensics experts to move in on Sunday before leaving.

By sunset, that second team had retrieved all the bodies, the commander of the army’s Landmine Field Clearing Battalion told reporters.

Explosives disposal experts had also started working at the site, although it looked like they would have to resume their efforts at dawn on Monday, local authorities said.

It was only when their work was done that Civil Aviation Authority experts would try to retrieve the plane’s black box.

The fire service and police have created an extended security perimeter because of the widespread ordnance. Residents have been allowed to leave their homes since early on Sunday, but have been told that their fields may not be safe to work in because of the likely presence of explosives. Nearby dirt roads have been closed to vehicles.

A plume of white smoke was still rising from the front end of the plane on Sunday morning.

The plane was operated by Ukrainian cargo carrier Meridian. The Ukrainian consul in Thessaloniki, who arrived at the crash site, told local officials that the crew were all Ukrainian.

“These were illuminating mortar mines and training (mines). This flight had all necessary permissions in accordance with international regulations,” Mr Stefanovic said.

The plane crashed shortly before 11pm about 25 miles (40km) west of Kavala International Airport.

Minutes before, the pilot had told air traffic controllers he had a problem with one engine and he had to make an emergency landing. He was directed to Kavala Airport but never made it there.

The plane is a Soviet-era four-engine turboprop cargo carrier.

Drone footage shows that small fragments are all that is left of the plane. Firefighters who rushed to the scene on Saturday night were prevented from reaching the crash site by smoke and an intense smell that they feared might be toxic.

Nearby residents were told to keep their windows shut all night, not to leave their homes and to wear masks.