Hopeful: Commuters will be without transport for most of the day

The industrial action comes a day after a strike by air traffic controllers forced the cancellation of hundreds of domestic and international flights.

Transport unions, led by the Cobas group, say the protest is against a pay deal made between the government and larger unions in December.

Further transport strikes and action by Alitalia staff are expected this year.

Government officials in Milan made efforts to mitigate the impact of Friday's strike by imposing an order guaranteeing some transport services during the morning and afternoon rush hours.

'Black Friday'

The minimum service was reported to have been scrupulously observed, allowing commuters to get to work before metro stations closed and buses and trams returned to their depots. A limited service is expected to run later to enable commuters to get back home.

The general lack of public transport has shifted the choas to the roads.

If they don't have a contract it is correct they protest Maria Franzoni, metro passenger

One taxi driver in Rome, battling through congested streets, said: "It's definitely going to be a Black Friday. Sure we get more work, but trying to actually get anywhere in this chaos is impossible."

But some members of the public showed their support for the striking workers.

Maria Franzoni, who caught an early train to get into work on time, said: "It was worrying, a lot of traffic and everyone was agitated but if they don't have a contract it is correct they protest."

Fireman Vincenzo Salga said he thought it was important to demonstrate for workers' rights and strike if necessary.

British tourists, the Muir family from Yorkshire, were caught up in the strike but also showed solidarity with the strikers.

"We're affected but we're tourists and we are only here for a couple of days, these people are working and they need money to live so we support that," said Mrs Muir.

She said she would have to tear up the bus tickets they had bought and walk instead.

More strikes

In December, Italy was almost paralysed by a series of wildcat strikes by transport workers.

The country's three largest unions reached agreement with the government, but the smaller unions say the agreed US$103 a month increase in pay is not enough.

A government agency enforced a holiday truce that banned transport strikes over Christmas between 18 December and 7 January.

Unions have also threatened another nationwide general strike if the government fails to meet their demands to change its plans to reform Italy's generous pension system.

Morena Piccinini, a senior official at Italy's largest union Cgilm, said: "If the government goes ahead with the pension bill, we can't rule out further industrial action."