Most of Italy's supplies move on wheels and little fuel was delivered to pumps on the second day of a five-day strike to back demands for lower gasoline prices and shorter working hours.

Unions walked out of a meeting Tuesday with Transport Minister Alessandro Bianchi, breaking off negotiations to end the strike.

Trucks blocked traffic on highways outside Rome, Milan and other major cities. Many gas stations across Rome were closed or put up signs reading "out of fuel." Long lines of cars and scooters formed in front of those still operating.

Old, rotting produce was all that was left on many supermarket shelves. Fresh meat, milk, fruit and vegetables were in short supply.

"Since yesterday we haven't had any deliveries," said Ruggero Giannini, sales manager at a supermarket in downtown Rome. "We are powerless in the face of such a situation."

Italian farm lobby Coldiretti said farmers would lose millions of dollars if tons of perishable goods remain undelivered. The distribution of animal feed was also threatened, a statement from the group said.

Gasoline stations associations said about 60 percent of pumps in the country had been idled and most of those remaining would be forced to shut down by Tuesday evening.

"The supply problem is causing a real paralysis," said Luca Squeri, head of the FIGISC gas stations federation.

Italian news reports said some drivers who refused to join the strike were attacked, and some of their vehicles were stoned, and had tires slashed.

Although the walkout had been announced, the authority that monitors strikes in Italy said that blocking traffic and essential supplies was unlawful and urged the Transport Ministry to order the drivers to return to work.