Budapest (AFP) - Several thousand people marched in Budapest Sunday to demand press freedom and protest against the sudden closure of Hungary's top-selling political daily Nepszabadsag which had criticised the government.

Prime Minister Viktor Orban has been attacked abroad for clamping down on opposition as well as for stifling basic freedoms and the paper's closure is viewed by critics as the latest example of his crackdown.

The 53-year-old premier's crusade to restrict critical voices in the media began soon after he won a two-thirds majority at the 2010 election.

The newspaper, with a staff of 90, was suddenly closed down last week. The management has said the decision was entirely an economic one and not politically motivated.

The marchers, numbering between 2,000 and 3,000 according to an AFP estimate, shouted slogans such as "They are stealing our freedom!" and held up banners like "Stop the dictatorship of Fidesz", the ruling party.

"We want that this ambiguous situation ends and the owner clearly says what he intends to do," said Peter Peto, the paper's deputy editor.

Nepszabadsag's publisher since 2014 is Mediaworks, owned by Austrian magnate Heinrich Pecina, who has said the paper's financial losses over the last decade were behind the drastic move.

And in extracts of an interview published online on Saturday Pecina defended the decision saying it had been governed by economics not politics.

"There is a mutual respect between me and Viktor Orban, but no form of dependence," he told the Austrian weekly Profil.

The ruling Fidesz party meanwhile held a parallel press conference that press freedom was guaranteed in Hungary.

Orban's Fidesz party has called the paper's suspension a "rational economic decision, not a political one", pointing to debts and a huge drop in sales.

But opposition parties, activists and journalists at the paper blamed the move on Orban's government cutting off oxygen for media that do not toe the government line.

They also said the timing was suspicious, coming a week after Nepszabadsag, which has often been critical of Orban, made corruption allegations against two close allies of the prime minister.