A bus carrying pilgrims to Mecca in Saudi Arabia caught fire after crashing into a bridge on Monday, killing 20 people and injuring around 30, according to Saudi state television.

The accident, which occurred in the southern province of Asir, highlights the ongoing challenge of safely transporting pilgrims to Mecca and Medina, Islam’s two holiest cities.

The accident happened in the first week of the Muslim fasting month of Ramadan, when many Muslims perform the Umrah (short pilgrimage), months before the annual Hajj pilgrimage.

“According to the preliminary information we received, the number of dead as a result of the accident reached 20 people, the total number of injured – about 29,” the state agency “Al-Ekhbariya” reports.

The victims are of “different nationalities,” according to the channel, which did not provide other details.

Al-Ekhbariya showed footage showing the reporter standing in front of what appeared to be the charred body of the bus.

Transporting pilgrims on Saudi Arabia’s roads can be dangerous, especially during the Hajj, when buses full of worshipers create endless traffic jams.

In October 2019, 35 foreigners were killed and four injured when a bus collided with another heavy vehicle near Medina.

Pilgrimages, however, remain an important part of the tourism sector Saudi Arabia’s leaders are counting on to diversify their fossil fuel-dependent economy.