In a letter to the Central Board of Secondary Education (CBSE), the government also cited the high positivity rate, the rising number of COVID-19 cases in the national capital and the lockdown imposed in the city till May 10.

The CBSE has said that the marks for Class 10 students will have to be submitted by schools by June 11 and the result will be declared by June 20.

''Keeping in view the ongoing situation, including its emotional ramifications, enforcement of lockdown and deployment of teachers for various duties, the competent authority of CBSE is requested to kindly review the Time Schedule... regarding Policy for Tabulation of Marks for Class X Board Exams 2021,'' the Delhi government said.

''Further, to assist the district administration, most of the teachers and other staff, including data entry operators and IT assistants of Delhi Government schools, are at the forefront of COVID-19 related duties,'' it said.

According to the letter, teachers are involved in conducting door-to-door surveys in COVID-19 hotspots and vulnerable areas, providing assistance with testing and contact tracing, monitoring the movement of bodies and ensuring timely disposal of calls for hearse vans. They are also engaged in activities related to COVID vaccination.

The teachers are also assisting the government in the enforcement of COVID protocols and screening at airport, it said.

The government said 76 of its schools are have been designated as COVID vaccination centres.

In addition to that, there have been several instances wherein teachers and students or their family members have tested positive for COVID-19 or have lost their dear ones, it said.

Delhi recorded 311 COVID-19 deaths and 20,960 fresh cases that pushed the toll to 18,063 and the infection tally to 12,53,902, according to a bulletin issued by the Delhi health department.

The CBSE had on April 14 cancelled Class 10 exams and postponed Class 12 exams in view of the surge in COVID-19 cases.