BEIJING — Beijing's education authority on June 15 ordered schools to reimplement closed-off management of campus, and allowed students to opt stay-at-home study mode amid ramped up epidemic control efforts.

A string of measures have been rolled out since last week as the Chinese capital reported a resurgence of domestically transmitted COVID-19 cases after a weeks-long lull.

The Beijing municipal education commission stressed that all prevention and control measures in schools must be strictly followed. Teachers, students and staff members should wear masks on campus.

Previously, nine grades in primary and middle schools across the city had resumed classes, involving some 840,000 students in more than 1,400 schools.

Li Yi, a spokesperson for the commission, said on June 15 the students can opt to study at home.

The municipal authorities have delayed the reopening of primary schools for first to third graders, scheduled for June 15, and suspended all sports events. Schools in Fengtai and Xicheng districts, where most of newly confirmed COVID-19 cases were reported, allowed on-campus classes only for graduating students.

"To ensure health and safety of every child, graduating students in junior high and senior high schools in the city should end their school days 14 days before exams at the end of the semester," Li said.