Cases soared to almost 4,000 on Tuesday in Romania and there were 96- virus-related deaths. It was the highest number of cases in 5 months.
The Strategic Communication Group said there were 675 patients hospitalized in intensive care units and more than 5,600 patients in hospital.
A total of 155 children with Covid-19 were hospitalized of which 10 are in ICU.
Almost 3 million students returned to schools on Monday as cases spiked.
Face coverings are compulsory for children and teaching staff inside schools to stem the spread of the virus.
Romanian President Klaus Iohannis urged people to respect the rules “to protect us and our loved ones.”
Authorities say that lessons will resume online if the infection rate exceeds 6 per 1,000 residents in an area.
Infections have soared from the low hundreds in recent weeks after the summer break. The spike in cases has been fuelled by a vaccine uptake of only 27%.
Romania reported 459 new cases on Tuesday and there were 215 cases in the northeast county of Suceava. There were 167 cases in the southwestern county of Timis, 155 in Maramureş and 134 in Cluj. Four other counties had more than 100 cases.
The national infection rate which is measured over a two-week rolling period was 1.19 on Tuesday.
Vaccine coordinator Valeriu Gheorghiţă said there was increased vaccination among the over 12s with 15% of the age group inoculated.