Greek officials are looking to reimpose coronavirus curbs following a surge in cases as authorities in Bangladesh and the United Kingdom also noted a spike in infections.
Greece on Tuesday reported a jump in daily coronavirus infections after many weeks of declining case numbers that prompted authorities to lift most COVID-19 restrictions.
Public health authorities reported 1797 new daily cases on Tuesday, more than twice the level of 801 cases reported on Monday, bringing the total number of infections to 429,144.
Coronavirus-related deaths have reached 12,754.
Greece, heavily dependent on tourism, has lifted most restrictions for travel and entertainment and scrapped mask wearing rules in outdoor spaces as cases fell.
But health experts have voiced concern over the coronavirus and its more contagious Delta variant after infections started rising again in recent days.
A government official said on Tuesday many of the new positive test cases are youngsters and are linked to entertainment, so authorities decided to reimpose restrictions on restaurants, nightclubs and bars later this week.
"Effective July 8, restaurants, bars, clubs and entertainment venues will operate only with sitting clients and in line with legislated capacity rules," Deputy Citizen's Protection Minister Nikos Hardalias said at a briefing.
Offenders will also face hefty fines, including suspension of their operation, Hardalias said.
"These emergency measures aim to contain the spread of the virus in younger ages so that we all have a freer but, most important, a safe summer," he added.
About 38 per cent of Greece's eligible population is fully vaccinated so far and the government has offered incentives to encourage more people to get the shot, including cash and free mobile data for youth as it wants to bring that rate up to at least 70 per cent by autumn.
Bangladesh on Tuesday reported 11,525 positive cases, the highest in a day since the start of the coronavirus pandemic.
Another 163 people died in the last 24 hours, raising the total number to 15,392, according to the government.
Bangladesh's cases of new infections increased last month when the Delta variant - first discovered in India - hit the country's border regions in the northern and southwestern Bangladesh.
Bangladesh shares a large border with India and health experts say the actual number of both infections and deaths is likely higher.
The country is facing a crisis in vaccination after India stopped exports of AstraZeneca shots because of its own outbreak in April.
Bangladesh has a deal to get 30 million doses from India's Serum Institute.
Only 4 million Bangladeshis have been vaccinated in a country of 160 million people.
Authorities are hoping to start a new mass vaccination campaign with China's Sinopharm and other vaccines.
Meanwhile, the UK reported the highest daily number of new infections since January 29 on Tuesday and the greatest number of deaths within 28 days of a positive test since April 23.
Tuesday's figures showed that there were 28,773 new cases, up from 27,334 on Monday, and 37 deaths.
As of the end of Monday, 86.2 per cent of UK adults had received one dose of a vaccination against COVID-19 and 64.3 per cent had received two doses.