The Dubai Civil Aviation Authority on Monday directed Air India Express to reject the negative coronavirus test reports of passengers from four Indian laboratories.

The laboratories are Suryam Lab in Jaipur, Microhealth Labs in Kerala, Dr P Bhasin Pathlabs (Private) Limited and Noble Diagnostic Centre in Delhi, the airline said in a tweet.

Passengers travelling to the United Arab Emirates need to carry a Covid-19-negative certificate from an RT-PCR, or reverse transcription polymerase chain reaction, test done 96 hours before the journey, according to the country’s rules. Children under the age of 12 and passengers with moderate or severe disability are exempted from the rule, according to The Times of India.

The United Arab Emirates has a list of designated laboratories, from which passengers from India, Pakistan and Bangladesh must obtain their certificates.

Earlier this month, Dubai’s aviation authorities had banned Air India Express flights for 15 days after the airline was found to have flown two infected passengers. The ban was revoked after the airline assured the authorities that such lapses will not happen again.

The UAE is one of 10 countries with which India has a bilateral air bubble agreement, according to PTI. The agreement allows two countries to operate two operate flights between them with certain restrictions.

The UAE has reported over 92,000 coronavirus cases and 413 deaths so far, according to Johns Hopkins University. India, on the other hand, is the world’s second-worst affected country with 60,74,702 cases and 95,542 deaths.

However, an analytical study by the Indian Institute of Technology, Mandi, had shown last week that travellers coming in from Dubai and the United Kingdom were the main sources of coronavirus importations into India. The study was published in the Journal of Travel Medicine.