* Government locks down swathes of northern Italy
* Schools, cinemas, museums closed across the country
* Milan bourse plunges 10%, fears for economy grow
* Six die in prison riots over coronavirus restrictions (Adds parliament agreement to vote deficit hike)
MILAN, March 9 (Reuters) - Closed shops, plunging stock markets and prison riots marked the first day after Italy locked down much of its northern region in a bid to fight the coronavirus outbreak with some of the most draconian control measures since World War Two.
Faced with Europe's most serious outbreak of the highly contagious virus, Italy imposed strict controls on travel from the northern region of Lombardy and parts of neighbouring Veneto, Piedmont and Emilia-Romagna.
The government also ordered cinemas, theatres and museums to close, cancelled sporting events and told shops and restaurants to ensure that patrons remained at least a metre apart.
Parliament has virtually closed down due to contagion fears, meeting just once a week to prevent a huge backlog of work.
The measures, unprecedented in Italy's postwar history, tightened controls including school closures that were imposed after the coronavirus emerged in a small town outside the financial capital Milan last month.
In a little over two weeks, the number of recorded cases has surged to 7,375 with 366 deaths, putting the health system under massive strain, with intensive care facilities struggling to handle the influx of new cases.
"We have two objectives, contain the spread of this virus and strengthen the health system so that it can meet this challenge," Prime Minister Giuseppe Conte said in an interview with the daily La Repubblica. "We're a strong country."
In Milan, public transport was working but streets were much quieter than normal, with many smaller shops and cafes closed. Even among those left open, most remained empty, meaning any requirement to maintain a distance of at least a metre between customers was purely theoretical.
"There's been nobody at all. I've never seen anything like it," said a shop assistant at the Rinascente department store in the city centre.
Like other central shops, the store, normally packed at lunch time, was virtually empty. The black-clad sales assistants chatting to each other by the display stands appeared to outnumber shoppers by at least 10 to one.
Fashion retailer Calzedonia said it was closing its stores in the affected areas until the crisis passed.
But the most dramatic illustration of the shock came in the country's overcrowded prisons where inmates rioted in jails across the country. In Modena, in the red zone, six prisoners died in a riot apparently triggered by restrictions on visiting rights imposed to fight the virus.
The World Health Organization said aggressive measures were warranted to stop the spread of the virus.
"What is critical at this stage is that everybody join the efforts and do their part," a spokesman said.
But with Italy on the brink of recession, the government's steps have come at an economic cost.
Clamping down on movement in and out of Lombardy, including the financial capital Milan, and other large parts of the north, will take a heavy toll on economic growth in Italy's wealthiest and most productive region.
The Milan bourse, which was down some 17% since the outbreak in northern Italy, plunged at Monday's opening, with the blue chip FTMIB index down 10% at 1430 GMT.
At the same time, the spectre of past crises returned as Italy's cost of borrowing shot up. Government bond yields rose sharply, pushing the gap between Italy and benchmark German 10-year bond yields above 200 basis points for the first time since August 2019.
The government has promised 7.5 billion euros ($8.57 billion) to alleviate the economic impact of the crisis, and parliament will vote on Wednesday to approve the resulting hike in the budget deficit to 2.5% of national output from 2.2%.
The 630-seat Chamber of Deputies agreed on Monday that only 350 of its members, mainly from less affected central and southern regions, should turn up to vote, allowing the northern ones to remain at home.
"I've got a two-and-a-half-month-old baby and I could never forgive myself if I gave him something," a deputy from Milan told Reuters. (additional reporting by Giuseppe Fonte and Gavin Jones; Writing by Giulia Segreti; Editing by Crispian Balmer and Janet Lawrence)