(Repeats story without changes)
By Matt Robinson
MARIUPOL, Ukraine, May 11 (Reuters) - The two men crouched in the shade of a tree. The ballot papers they were accused of forging lay on the front of their Russian-made Moskvich car, stopped and searched by Ukrainian soldiers on the outskirts of the port city of Mariupol, in the country's rebel southeast.
"This is how they did it in Crimea," said warrant officer Timofey Rudyak, who like the other soldiers had been sent 750 km (500 miles) from the capital, Kiev, to restore order to the country's industrial heartland.
Rudyak, 35, said the several hundred ballots, bound in white paper and almost all ticked 'Yes', had been intercepted little over an hour after voting began in a referendum on self-rule; a vote dismissed by Ukraine's government and its Western backers as a sham, a repeat of the vote that saw the Crimean peninsula annexed by Russia in March.
Reuters did not witness the initial stop-and-search, nor was this reporter allowed by the soldiers to speak to the suspects.
Whatever the truth, the scene that followed - police rebuffed, an armed standoff in the middle of a road - spoke less about possible vote fraud than the dangerous collapse in trust and order that threatens Ukraine with civil war.
Four police officers arrived, demanding to take the men away. The soldiers of the 72nd Mechanised Brigade, speaking Ukrainian to each other but Russian to the police, refused. After tense words and several phone calls, the police left.
"We don't trust them," said Rudyak. "When so-called peaceful citizens shoot at us from behind the backs of the police, how can we trust them any more?"
A short time later, the soldiers cocked and raised their rifles, pointing them at a white, unmarked van that had pulled up at the checkpoint. The doors opened and more guns appeared, held by masked men in mismatched black uniforms, some in sneakers and combat trousers.
They identified themselves as National Guard troops, which operate under Ukraine's interior ministry. One produced handcuffs and tried to take the suspected ballot-riggers away, but was again refused by the army.
Only when two plain-clothed officers of the Ukrainian state security service (SBU) turned up did the soldiers stand down. The evidence was filmed and photographed, before being set alight by the soldiers.
The security forces in the Donetsk and Luhansk regions, where many of the 6.5 million people are Russian-speakers, have become riddled with suspicion, forced to take sides as Ukraine and the pro-Russian rebels gird for possible full-blown war.
"IT'LL BE WAR"
The police in this steel and coal belt abutting Russia have chosen the path of least resistance in the face of armed militiamen and mobs demanding the region break away from Kiev.
Many have actively crossed sides, creating a security vacuum filled by gunmen. The National Guard, too, has come under pressure, living as they do in the midst of militiamen and mobs that cruise the street, attacking state buildings and barracks at will.
Violence exploded on Friday in this city of half a million, the second biggest in the self-proclaimed Donetsk People's Republic, when the army opened fire from infantry fighting vehicles and automatic rifles on a police station they said had been taken over by pro-Russian militants.
But the police were still there, as evidenced by the dead body of one on the pavement and others who hurriedly collected their uniforms and belongings the next day. Between seven and 20 people were killed, depending on whom you believe.
The assault was cited by many voters on Sunday in Mariupol who said they had ticked 'Yes' to break with Kiev, though they differed on what exactly that meant - autonomy, independence or eventual annexation by Russia.
They all agreed on their contempt for the government in Kiev, which they say came to power illegally with the overthrow of Moscow-backed President Viktor Yanukovich in February after months of mass protests and 82 dead in gun-battles with police.
On the city's main square, fire-fighters doused flames still licking the windows of the City Hall, abandoned by pro-Russian militiamen and activists and set ablaze during the violence on Friday.
A woman in high heels, surgical mask and police jacket fiddled with handcuffs and posed for a photographer, a moment of surrealism increasingly in keeping with a city spinning out of control.
A local media report, which Reuters could not confirm, said the city's police chief, Valeriy Andryshchyuk, had been hanged by a militia in a forest in northern Mariupol after being sentenced to death by a self-proclaimed People's Court.
Adding to the cocktail of security forces, a company partially owned by Ukraine's richest man, Rinat Akhmetov, said it was deploying a volunteer militia in Mariupol made up of steel workers, and urged Kiev to keep the army out.
A separatist leader in Donetsk said the region would form its own military as soon as the referendum results were announced. The Ukrainian army, Denis Pushilin said, would be considered "Illegal and declared occupiers."
Rudyak, the Ukrainian warrant officer, watched as a black Landcruiser pulled up at the checkpoint, greeted with raised rifles because its front licence plate was not visible. The driver flicked a button and the plate rotated, revealing it was registered in Lviv, a western city that is the heart of Ukrainian nationalism.
"Not wise to travel with those plates in these parts," said Rudyak. He predicted revenge for Sunday's arrests would be swift.
"We'll have guests tonight. It'll be war." (Writing by Matt Robinson; editing by Ralph Boulton)