In Torez, some say missile's journey through town has been a hot topic but people are scared of talking to outsiders

Claims by pro-Russia separatists in east Ukraine that they have never been in possession of the missile launcher apparently used to down flight MH17 are looking increasingly flimsy, as several witnesses told the Guardian they had seen what appeared to be a Buk missile launcher in the vicinity of the crash site last Thursday.

The sightings back up a number of photographs and videos posted online that put the Buk system close to the crash site on the day of the disaster. Just before lunchtime last Thursday, prior to the Malaysia Airlines plane's takeoff, a Buk was driven through Gagarin Street, one of the central thoroughfares of Torez, witnesses said.

Torez would later be the town where bodies of the victims were loaded on to refrigerated train cars. The tarmac on Gagarin Street is strewn with ruts made by tank treads, and locals say armoured vehicles controlled by separatists driving through the town have become a regular occurrence in recent weeks. The convoy last Thursday was different, however.

"We were inside and heard a noise much louder than usual," said one shopkeeper, who did not want to be identified. "We came running out and saw a jeep disappearing into the distance with something much larger in front of it. Later, customers said it had been a missile carrier."

In another shop further down the street, there was talk of a convoy of two jeeps and a missile launcher covered in a net driving past in the direction of the town of Snizhne. "I've never seen anything like it," said a middle-aged woman. She said her husband showed her a photograph of a Buk launcher afterwards and she realised that was indeed what she had seen. A group of men also said they had seen a Buk.

There have been suggestions that the missile was fired from fields on the outskirts of Snizhne. Many in Torez did not want to speak about the Buk or claimed not to have heard anything about it. Others said the missile's journey through the town had been a talking point in recent days, but people were scared of divulging too much to outsiders. None of those who reported sightings of the Buk wanted their names published.

Armed rebels at a checkpoint outside the entrance to Snizhe were turning away cars with journalists on Tuesday, saying they had received orders not to let the press into the town.

Ukrainian intelligence has suggested that the missile launcher was provided by Russia and taken back across the border after the deadly attack on MH17. "It is most likely that the machinery which fired the missiles at Malaysian aircraft will be destroyed and the people who committed the act of terror will be annihilated," said Anton Gerashchenko, adviser to Ukraine's interior minister.

Russia has denied giving the rebels a Buk launcher, and suggested the Ukrainian army had a number of Buk systems in the vicinity. They have also claimed that a Ukrainian fighter jet was in the vicinity of MH17 at the time of the crash.

The self-styled prime minister of the Donetsk People's Republic, Alexander Borodai, again denied that the rebels were responsible for the crash in a statement to the press in the early hours of Tuesday morning, before he handed the flight's black box recorders to a visiting Malaysian delegation. Ukraine had the "technical ability and the motive" to carry out the attack while the rebels had neither, he said.

However, the rebels had downed a number of Ukrainian planes in the area in recent weeks, and while the presence of the Buk in rebel-controlled territory on the day of the crash does not prove that rebels launched the missile, it does show they are lying about not having any of the systems under their control.

US officials have said they have satellite evidence that a missile was launched at MH17 from the region of Snizhne last Thursday, and were due to make the evidence public later on Tuesday.