Malaysia Airlines will cut capacity by 20% across its network as the carrier struggles with a shortage of maintenance staff and delayed deliveries of new aircraft.

The reduction will affect domestic routes, as well as international operations to Australia, China, South Asia and the Middle East, Malaysia Aviation Group said in a statement Thursday. Flights operated by low-cost arm Firefly and pilgrimage unit Amal will also be impacted, and affected customers will be offered refunds or rebooking, according to the statement. 

Malaysia’s flag carrier has had multiple operational and technical issues in recent weeks, prompting the country’s aviation regulator to cut the validity of its operator certification period to a year from the usual three years, the Star newspaper reported citing Transport Minister Anthony Loke. 

The airline also blamed new aircraft delivery delays for its network reduction. Malaysia Air has only received 4 of the 13 Boeing Co. 737 Max jets it was due to receive this year, and said Airbus SE will only deliver 3 of the 4 A330neo widebody planes that were due to arrive in 2024. 

Several airlines have warned in recent days about the impact of aircraft delivery delays on their operations. Both manufacturers are struggling with persistent part shortages and Boeing faces additional scrutiny following a midair blowout on one of its jets early this year.

In addition to new jet deliveries, Malaysia Airlines is also experiencing an attrition of skilled workers as new maintenance and repair players enter the Malaysian market, and said that the supply chain issues affecting the aviation industry have meant that it is taking longer to repair and overhaul aircraft.