KARACHI (REUTERS) - Pakistan's aviation regulator has made masks mandatory on domestic flights given a gradual rise in the number of Covid-19 cases across the country, it said a statement.

The order comes a day after Pakistan's biggest city, Karachi, reported that its Covid-19 positivity ratio, or the rate of positive cases out of all tests conducted, rose to 21 per cent compared with a national rate of 2.8 per cent.

"With immediate effect, mask wearing will be mandatory on-board domestic flights," the Pakistan Civil Aviation Authority (PCAA) said in the statement late on Sunday.

Pakistan has had very few Covid cases over recent months and had done away with almost all precautions.

But over the past 24 hours, the national Covid positivity ratio had risen to 2.85 per cent with 382 positive cases and two deaths, according to data released on Monday by the National Institute of Health, Islamabad (NIH).

A month ago, the positivity ratio was 0.54 per cent with 79 positive cases and no deaths. According to the NIH, 85 per cent of eligible Pakistanis have been fully vaccinated against Covid-19.

Pakistan disbanded the National Command and Operations Centre, which was overseeing the Covid-19 response, on March 31 as infections fell to the lowest since the outbreak began in 2020.