Istanbul (dpa) - The Turkish government on Saturday reported a limited number of violations against a two-day partial lockdown to contain the new coronavirus that was announced with little warning.

Authorities have started legal proceedings against a total of 2,756 people in the 31 largest cities, the Interior Ministry said, according to state news agency Anadolu.

Turks in those cities, which include Istanbul and the capital, Ankara, are banned from leaving their homes from Friday midnight until midnight on Sunday.

Interior Minister Suleyman Soylu insisted late Friday that the curfew would not be extended.

It was not immediately clear if all of those who defied the lockdown were fined, and by how much.

"Almost all" of the citizens affected by the curfew have stayed home, the ministry said, adding that the lockdown covers nearly 64 million people in the country of 83 million.

The curfew announcement came only two hours before midnight on Friday, leading thousands of people to crowd grocery stores, defying the virus measures. Only bakeries, pharmacies and some petrol stations are allowed to stay open during the curfew.

Social media was flooded with images from across the country showing people swarming small shops, panic-buying essential goods as water and bread. Fights broke in some instances.

The opposition criticized the government for the sudden decision, which it said led to even further confusion. Istanbul Mayor Ekrem Imamoglu said his office was not informed about the curfew decision.

Turkey has so far reported about 47,000 cases of infection and 1,006 deaths, with 60 per cent of cases in Istanbul.

The increased traffic on the streets late Friday threatens to accelerate the spread of the disease, warned Tevfik Ozlu, a member of a science board that advises the government on virus measures.

There could be negative effects in "a week to 10 days," he said in a televised interview, warning of a "scary possibility of infection."

The weekend curfew is the strictest measure Turkey has taken so far.

Prior to it, people over 65 years of age, the chronically ill, and those under age 20 have been banned from leaving their homes.

Other measures include the closing of schools, universities and public spaces, and a ban on large events and mass prayers in mosques.