The Saciris and others have improvised a head start, stripping down old French cars and turning them into primitive pick-ups which have been likened to the post-apocalyptic machines in Mel Gibson's "Mad Max" movies.

By tearing off the body and leaving little but the engine and wheels on decades-old Citroen Dyane cars bought cheaply, they hope to avoid license plate or registration paper checks while working more quickly and easily.

It enables them to cover more suburbs than by foot, said 21-year-old Malic Saciri, the oldest of 11 brothers and sisters living in poor and dirty conditions on the city's outskirts.

He said there were many similar vehicles in Belgrade, although police have become tougher and often impose fines, forcing some off the streets.

"There is no way I'm going to push a cart full of cardboard up the hill," said his brother Tus. "I'm not giving up this Dyane," said the 17-year-old, standing proudly next to his 'papermobile' fitted with a purpose-built bin in the back.

Bearing little resemblance to the car it once was, a plastic bottle serves as fuel tank. With no hood, windows or instrument panel the driver sits unprotected out in the open. He starts the engine by connecting the battery and pushing a button.

Like many other Roma children, Tus does not attend school but he has become a skilled, if self-taught, car mechanic. "I have to work every day. That's life."

"DYANCHEROS"

Boris Mitic, a Serbian film director who has made a documentary called "Pretty Dyana," said the Roma favored the Citroen Dyane because it was one of few cars from which the outer shell could be removed without damaging the chassis.

The Dyane, a model which followed Citroen's more famous 2CV, is affordable at roughly 200 euros ($240) in a city full of old and run-down cars, and also has good suspension. "The Dyancheros, as I call them, can collect several tons of recyclables in a day this way, easily outperforming the cart-pushing competition," Mitic said.

"Dozens of these unlicensed Mad Max mobiles patrol the suburbs of Belgrade, assuming the role of the only recycling service in the local infrastructure," he said.

The Saciri family is among roughly 400,000 Roma in Serbia and Montenegro, the state union that last year replaced what remained of Yugoslavia after a decade of wars in the 1990s.

They face similar problems as ethnic kin elsewhere in former communist eastern Europe - poverty and discrimination.

The vast majority have no formal employment and the few who do have a steady job earn only a third of the average salary, which now stands at about $240 a month, according to a report by the United Nations Development Program last year.

"The plight of the Roma population in Serbia has been made worse by crisis and conflict during the last 10 years," it said.

Those displaced from the southern province of Kosovo, like the Saciri family, are among the most vulnerable and marginalized. They often live in illegal settlements without access to electricity, drinking water and sewage.

"We get no help from the outside," said Dzedzvet Saciri, the father. "They are ignoring us. They don't even come to see us."

He said the family received only 4,000 dinars for two tons of cardboard, representing a week's work. "Tell me what you can buy for that. I have a family of 11. Do your own maths."

The family fled Kosovo after the 1999 war between Serbian forces and independence-seeking Albanian rebels. Many in the Albanian majority accused Roma of collaborating with Serbs during the repressive rule of Slobodan Milosevic.