Employees of Russian airlines and airports began receiving recruitment notices after President Vladimir Putin ordered a partial military mobilization, the Kommersant newspaper reported on Friday, citing sources close to the situation, Reuters and news.ro reported.

Employees of at least five airlines, including Russia’s top airline Aeroflot, and workers at more than 10 airports were notified within a day after Putin ordered the mobilization, the newspaper reported.

According to sources in the three companies, 50-80% of employees can be drafted, and a source close to “Aeroflot” says that in the three airline groups, more than half of the staff can be drafted, “Kommersant” writes.

Aeroflot declined to comment.

Most aviation pilots are reserve officers who have been trained in military departments of flight schools or soldiers who have completed military service.

At least five companies have begun to compile, and two have already sent lists of employees who are exempted from mobilization, as the layoff is critical not only for pilots and air traffic controllers, but also for technical, commercial and IT specialists, writes Kommersant. reported

Putin on Wednesday ordered Russia’s first military mobilization since World War II and backed a plan to annex parts of Ukraine, prompting some Russians to flee the country.

Defense Minister Serhiy Shoigu said on Wednesday that about 300,000 reservists will be called up, and they will be specialists with combat experience.

All Russian males between the ages of 18 and 27 are required to complete a year of military service, although university students can instead train at a military college alongside their chosen course of study.