The men, most masked by balaclavas, many carrying baseball bats, some wearing sidearms, swarmed around the black Jeep Patriot.
They dragged out the four occupants - in black combat uniforms - snatching their guns, magazines of ammunition, and radio transmitters. Body armour was stripped from the captives, who were forced to kneel on the pavement. The number plates of the car were torn off and it was driven away at speed.
No one was quite sure just what had taken place in the centre of Donetsk. The SUV had been parked outside a branch of the UkrBusinessBank. The staff thought the occupants may have been a "maskashow", armed masked gunmen sent by commercial rivals to disrupt trading, not an infrequent occurrence in this wild east.
The bank is owned by the dentist son of Viktor Yanukovych, Ukraine's overthrown president. Serhiy Oksenuik, the deputy chairman, insisted he had no idea what the armed men were after, or if it had anything to do with the financial affairs of Oleksandr Yanukovych, who is reputed to have personal assets of US$500 million ($580 million).
Members of the "self-defence force" arrived; they were unaware, they professed, of the identity of those who had made off with the weapons and the vehicle. "It's a mystery," said Aleksandr. He was a berkut, the riot police disbanded by the Kiev Administration after 100 protesters were shot dead in the Maidan, now one of the mainstays of the militia of the People's Republic of Donetsk.
Six members of the city's police force watched what had been happening from across the road. They eventually took away the men in black, one of whom told me that they were a special forces unit from the Ministry of Interior.
"We have not been arrested, we have not been detained, as far as I can tell." They were from Zaporoshiya, 400km away, on an operation, he ventured. Was it to do with Yanukovych? "I can't say anything."
The police said later they were unaware of an authorised raid involving the former president's family. Meanwhile, four Kalashnikovs, four pistols and two combat shotguns had disappeared into the already bulging illicit arsenal in the streets. "It's a problem," acknowledged Aleksandr.
Eastern Ukraine is on the jagged edge of anarchy.
Not all the violence has been planned and executed by the separatists. There have been killings, often by men in black appearing out of black 4WDs, according to witnesses. The separatist leadership has repeatedly accused the Right Sector, an extreme nationalist group, of carrying out the attacks on behalf of the Kiev Administration. The Ministry of Interior's special units also wear similar combat kits, and the Interior Minister Arsen Avakov has been a fervent advocate of the "anti-terrorist mission" - although many of his accounts on his Facebook page, had been widely off the mark.
However, personal and commercial scores are also being settled - and there are plenty of people who would want to do so with the Yanukovychs.
There has also been a sharp rise in criminal acts, particularly with the use of firearms.
After a belated show of force, attacks on checkpoints around Slaviansk - where a lot of pro-Moscow strength is concentrated - and setting up of checkpoints around the city the government forces seem hesitant about what to do, despite daily claims from Kiev that the anti-terrorist mission is going full throttle. An attack on Kramatorsk Airport, where most of the troops are based, had led to many of the senior staff being evacuated, either to Odessa, or all the way back to Kiev.
After brief apprehension of a government counterattack, the militants have resumed their piecemeal takeover of the Donbass. They occupied state buildings at Konstantinovka on Monday and three more in the space of four hours at Luhansk, where they had been holding the intelligence headquarters for weeks.
Two more buildings were occupied yesterday at Horlivka, the place from where a local politician, Vladimir Rybak, was abducted, tortured and murdered.
There were bitter complaints from Kiev that the police had done nothing to counter the attacks. The country's interim President Oleksandr Turchynov stated: "The vast majority of law enforcement officials in the east are not fulfilling their obligation to protect our citizens."
This is not the first time he and his ministers had made that charge; citizens, meanwhile, continue to be unprotected.
Outside the Donetsk administrative building under separatist control, I ran into a young man, one of the few with their faces uncovered, who was gathered around the SUV.
"What exactly happened there?" I asked. The young man shrugged: "You can't tell who is who now with everyone wearing masks, carrying guns. They could be anyone, dangerous people, you see how fast they moved with all that stuff?"
Where did his own allegiance lie? "I am just an ordinary citizen of Donetsk Republic, helping out," he smirked, twirling his baseball bat.