Greek hoteliers on Friday warned that the tourism sector, which makes up around a quarter of the economy, faced a "general disaster" if lockdowns linked to the coronavirus pandemic stretched beyond May.

"None of us want to consider that we will not be working after May," Grigoris Tassios, head of the Hellenic hoteliers federation told state TV ERT.

"If this happens we are heading towards general disaster, not only for the (tourism) sector but for the national economy," he said.

Greece's tourism ministry on Thursday ordered a temporary shutdown until the end of April of full-time hotels to limit the spread of the coronavirus.

The merchant marine ministry on Friday said travel to the Greek islands would be barred to all but permanent residents as of Saturday.

And the interior ministry warned Greeks against rushing to the countryside, where local health centres are inadequate to handle virus cases.

"We must not return to our home villages because this places a far greater burden on the situation," said Interior Minister Takis Theodorikakos.

"It's going to be a very difficult year," Tourism Minister Harry Theoharis told Open TV on Friday, adding that the sector was still trying to recover from the collapse of British travel giant Thomas Cook in September.

Seasonal hotels were shuttered days earlier.

"To protect hotel staff, the government has decided to suspend the operation of all-year hotels to the end of April," the ministry said.

The measure will take effect on Sunday.

Greek islands are now for residents only
Greek islands are now for residents only AFP / LOUISA GOULIAMAKI

The ministry said three hotels apiece would be allowed to operate in Athens and Thessaloniki, and one per regional capital.

Officials have not specified what will happen with hotels hosting migrants -- although the government had already announced earlier this month plans to end subsidised accommodation for them.

There are six confirmed deaths from COVID-19 in Greece. Two more deaths were reported on Friday.

Greece had already progressively tightened restrictions on trade and public gatherings.

The Hellenic chamber of hotels this week said it calculated a 522-million-euro ($572-million) blow to the tourism season because of the virus.

It added that over 92 percent of its members had already seen a drop of more than 70 percent in room bookings.

At peak season in the summer, Greek hotels alone employ over 200,000 people.

The Greek government has announced a support package of around 10 billion euros, including EU funds, to help shore up the economy.

Tassios said much would depend on how the outbreak of the virus unfolds in the rest of Europe.

Britain and Germany in particular are among Greece's top markets.

"We'll have to see if we'll even want to be bringing people in after April," he told ERT.

According to the Bank of Greece, the country's tourism sector in 2019 saw a 12.8-percent increase in earnings to 18.15 billion euros, and a 4.1 percent increase to 31.3 million visitors.