Huge plumes of black smoke could be seen rising over the site which was popular with Vietnamese merchants.

The fire brigade said more than 80% of the Marywilska 44 shopping complex was affected in the Bialoleka district of Warsaw, and that the roof fell in.

Police reported no injuries but that traders were in despair at the loss of their livelihoods.

The Gazeta Wyborcza daily reported that some Vietnamese vendors wanted to enter to save their goods from the complex but were blocked by security guards.

The Association of Vietnamese Entrepreneurs in Poland said the fire meant “great financial losses for merchants”, calling it a “terrible tragedy for thousands of merchants and their families”.

Chemical and environmental rescue specialists were among the large numbers of officials who took part in the operation. Authorities sent a text message warning Warsaw residents about the fire and telling them to stay home with the windows closed.

Mirbud, an industrial construction company listed on the Warsaw Stock Exchange, owns the shopping centre.

Warsaw police said it has begun investigating the fire, which started at around 3.30am local time, but has not yet determined the cause.

The Warsaw city administration planned on Monday to discuss financial support for the small traders whose livelihoods were destroyed.

Shopping centres and large shops are usually closed on Sunday due to a ban on trade imposed by the previous government, which had close ties to the Catholic church. However, small business owners are exempt from the ban, and many of the small shops at the centre opened on Sundays.