Adam Niedzielski told a press conference: "We have taken a decision that the regulations that are currently in force will be extended by a further period, by over a week, the extension will be binding until April 18."
The government had introduced tighter restrictions in late March owing to a third wave of infections, which had been due to expire on April 9.
Currently, nationwide restrictions include the closure of furniture and DIY stores, hairdressers and beauty salons, kindergartens and creches (with the exception of childcare for the children of medical staff, social workers and law enforcement, among others).
New limits have also been imposed on shops and places of worship. A limit of one person per 15 square metres (sqm) applies to shops of up to 100 square metres, with the space requirement increasing to one customer per 20 square metres in stores of over 100 square metres. The limit in places of worship is one person per 20 square metres.
Shopping centres remain closed except for grocery stores and pharmacies, as do hotels with the exception of hotels for workers and medical staff. Also closed are gyms, fitness clubs, cinemas, museums, theatres and entertainment venues, Restaurants are permitted to run only a takeaway service.
The wearing of face masks in public is mandatory nationwide as is maintaining a 1.5-metre distance from other people.
Niedzielski also said on Wednesday that the so-called British variant of SARS-CoV-2 is now dominant in Poland, accounting for 90 percent of all cases. There are also individual incidences of infection with the South African and Brazilian strains of the virus. (PAP)