LISBON, Sept 23 (Reuters) - Portugal will lift almost all remaining COVID-19 restrictions, allowing full occupancy in restaurants and cultural venues from Oct. 1, Prime Minister Antonio Costa said on Thursday. "As most of the restrictions imposed by law disappear, we are going to enter a phase that is based on the responsibility of everyone," Costa told a news conference. "We must not forget that the pandemic is not over," he said. Among the few measures that remain in place, mask-wearing is compulsory in public transport, at large events, in nursing homes, hospitals, shopping malls and hypermarkets. Masks ceased being compulsory outdoors last week. As Portugal has now fully vaccinated more than 8.5 million people, or 83.4% of its population, nightclubs and bars will be allowed to reopen, after having been shut since March 2020, Costa said. However, customers will have to show a digital vaccination certificate or a negative COVID-19 test. From Oct. 1 there will no longer be limits to the number of people allowed to sit together in restaurants and cafes, or to attend cultural events, weddings and baptisms. Digital certificates or negative tests will no longer be mandatory in hotels and gyms, but will still be required for air or sea travel, or to attend major cultural or sporting events, Costa said. After suffering in January what was then the world"s worst surge of infections, Portugal ramped up its vaccination campaign over the summer and now leads the world in terms of the percentage of fully vaccinated population, according to ourworldindata.org online publication. Portugal reported 885 new COVID-19 cases on Thursday and five deaths. That brings the total tally of cases to 1,064,876 - or around one in 10 Portuguese - and 17,938 deaths.