The US aviation regulators downgraded the safety ranking of Pakistan’s civilian airline system in the latest action following revelations that hundreds of commercial pilots received faked licenses, reported Bloomberg.

The Federal Aviation Administration (FAA’s) action on Monday adds another hurdle to Pakistan International Airlines Corporation’s ability to operate into the US, effectively blocking any carrier from that country from adding flights.

The decision, disclosed on an FAA spreadsheet that was posted on an agency website and confirmed by an agency official, means the US air safety agency determined Pakistan does not achieve international standards and now has a Category 2 rating.

The new rating means Pakistan airlines could be subject to additional inspections at US airports and could not add additional flights.

The US Transportation Department earlier this month separately notified PIA it was halting all operations as a result of the scandal. The European Union took similar action last month.

The FAA’s ranking system, known as the International Aviation Safety Assessment Programme, audits countries to see whether they meet the minimum standard for aviation safety set by the United Nations’ International Civil Aviation Organization.

PIA had received special permission to fly to the US this spring after several years of not operating there.

Pakistan said last month that 262 out of over 850 airline pilots had fake certificates and didn’t actually take the government’s qualification exams.

The Pakistani aviation industry has been under scrutiny following the crash in Karachi that killed all but two of the 99 people on board a PIA jet that landed on a runway without first putting down the landing gear, damaging its engines. The pilots had been distracted by discussing Covid-19, according to preliminary information on the crash.