Three London branches of Wahaca remained shut this weekend, after a suspected norovirus outbreak led to hundreds falling ill across nine chains of the Mexican restaurant.
UPDATE: Wahaca has now reopened all its restaurants. Read more here.
Soho, Covent Garden and Oxford Circus are all still closed. The White City branch had reopened, but closed again on Saturday, before reopening again on Sunday. Canary Wharf restaurant has also opened its doors to customers once more.
A spokesperson said there would be an update on the situation tomorrow.
Wahaca had shut nine branches because of the infection, with Public Health England (PHE) beginning an inquiry after hundreds of staff and customers fell ill.
The other affected restaurants were Manchester, Cardiff, St Paul's and Brighton.
Co-founders Thomasina Miers and Mark Selby said in a statement: "We assessed each case and when it became clear they were not isolated incidents, we got in touch with relevant officials at PHE and Environmental Health Officers."
Staff members who reported the illness remained off site until their symptoms had ceased for at least 48 hours.
Miers and Selby said the remaining closed restaurants would be reopened "on a case by case basis, as soon as we feel ready to do so".
On Thursday, when the news first broke, Deborah Turbitt, London deputy director for health protection for PHE, said the source of the norovirus outbreak was yet to be determined.
She said: "We have so far been made aware of 205 staff and 160 members of the public reporting illness, however these are unconfirmed ccases."
Norovirus is one of the most common stomach bugs, causing diarrhoea and vomiting, and can be caught at any time of the year. It can spread rapidly in public places and can be caught through close contact with someone with the virus, touching contaminated surfaces or eating contaminated food that has been handled by an affected person who has not washed their hands.