A job advertisement to recruit 30 female train drivers in Saudi Arabia has attracted 28,000 applicants, highlighting the scale of pent up demand as the kingdom opens up more opportunities to women.

Spanish railway operator Renfe said on Wednesday that an online assessment of academic background and English language skills had helped it to reduce the number of candidates by approximately a half, and it would work through the rest by mid-March.

The 30 selected women will drive bullet trains between the cities of Mecca and Medina after a year of paid training.

Renfe, which said it was eager to create opportunities for women in its local business, currently employs 80 men to drive its trains in Saudi Arabia, and has 50 more under instruction.

Job opportunities for Saudi women have until recently been limited to roles such as teachers and medical workers, as they had to observe strict gender segregation rules. Women were not even allowed to drive in the kingdom until 2018.

Female participation in the workforce has nearly doubled in the last five years to 33 percent amid a drive by the Saudi Crown Prince Mohammed bin Salman to open up the kingdom and diversify the economy, and women are now taking up jobs once restricted to men and migrant workers.

But the proportion of women working in the kingdom was still about half that of men in the third quarter of last year, at 34.1 percent, and female unemployment was well more than three times higher than for men, at 21.9 percent.

Saudi Arabia is highlighting progress on gender issues at a time of scrutiny in the West for its human rights record, including a crackdown on dissent that ensnared dozens of women’s rights activists and the 2018 murder of Saudi journalist Jamal Khashoggi.