The education ministry in a media statement on Thursday extended the shutdown of all secondary and higher secondary educational institutions until Aug 31.
All the educational institutions in the country have been closed since mid-March last year.
Initially, the government had announced the restart of schools and colleges by the end of March this year, but the resurgence of coronavirus infections scuppered the plan after highly contagious variants of the coronavirus were detected.
But a spike in the infection rate due to the Delta variant, which was first detected in India, forced the decision to be withdrawn.
As the Delta variant has become dominant, the death toll from COVID-19 in Bangladesh crossed 20,000 on Wednesday. The caseload now tops 1.2 million.
The education ministry said the closure of all educational institutions, including Qawmi madrasas, has been extended keeping the health safety of all students, teachers, officials and parents in mind amid the ongoing lockdown and the worsening coronavirus crisis in the country.
The ministry said the decision was made in consultation with the National Technical Advisory Committee on COVID-19.