SEOUL, May 19 (Yonhap) — The number of domestic air travelers hit a record low in more than two decades in April due to the coronavirus impact on the airline industry, industry data showed Tuesday.

The number of passengers on the domestic routes plunged to 1.35 million last month, down 22 percent from 1.74 million a month earlier, according to Air Portal, an aviation data provider operated by the Korea Civil Aviation Association (KCA).

The April figure marked the lowest level since January 1997. It is also sharply down from 10.63 million passengers on the domestic routes in January, the data showed.

Local airlines have suspended most of their flights on international routes since March as an increasing number of countries have closed their borders or have taken other measures related to incoming passengers due to concerns over the coronavirus pandemic.

In May, Air Portal said it expected travel demand to recover compared with last month as domestic air travel demand is on the rise as the COVID-19 outbreak seems to have passed its peak.

From May 1-17, the number of domestic air travelers jumped 55 percent to 1.04 million from 8,143 in the same period of last month, Air Portal said.

Korean Air Lines Co. and Asiana Airlines Inc., the country’s two biggest carriers, plan to start resuming flights on dozens of their international routes in June as they prepare for increased travel demand after countries ease entry restrictions.