Tigray refugees who fled the conflict in the Ethiopia's Tigray ride a bus going to the Village 8 temporary shelter, near the Sudan-Ethiopia border, in Hamdayet, eastern Sudan, Tuesday, December 1, 2020. (Photo by Nariman El-Mofty/AP Photo)

Romanian military doctors and medical students sit on a bus behind steamy windows before the National Day parade in Bucharest, Romania, Thursday, December 1, 2016. Military planes and helicopters flew over the Romanian capital Thursday as thousands turned out to celebrate the national day, marking the date when the country reunified with Transylvania in 1918. (Photo by Vadim Ghirda/AP Photo)

Retired Malam Jabba engineer Akbar Ali skis down the piste at the ski resort in Malam Jabba, Pakistan February 7, 2017. Atop the piste of Malam Jabba in Pakistan's once dangerous Swat Valley skiers schuss downhill, a new Chinese-built chairlift ferries tourists to the peak, and a luxury hotel is under construction to replace one torched by the Taliban. (Photo by Caren Firouz/Reuters)

In this picture taken Thursday, April 14, 2016, a Syrian man carries a carpet as walk through a devastated part of the town of Palmyra as families load their belongings onto a bus in the central Homs province, Syria. Thousands of residents of this ancient town who fled Islamic State rule are returning briefly to check on their homes and salvage what they can – some carpets, blankets, a fridge or a few family mementos. There is no water or electricity in the town, and it will be at least few months before anyone can return to stay. (Photo by Hassan Ammar/AP Photo)

North Korean cheerleaders arrive at a rest stop, or service station, as their bus convoy carrying a 280- member delegation on its way to the 2018 Pyeongchang winter Olympic games, makes its way past Gapyeong on February 7, 2018 More than 200 young North Korean women arrived in South Korea to root for athletes from both sides of the peninsula at the Winter Olympics. (Photo by Ed Jones/AFP Photo)

A protester throws a stone towards a burning police bus in front of him, during clashes with police, in central Kiev, Ukraine, Sunday, January 19, 2014. Hundreds of protesters on Sunday clashed with riot police in the center of the Ukrainian capital, after the passage of harsh anti-protest legislation last week seen as part of attempts to quash anti-government demonstrations. The violent scenes further escalated this ex-Soviet republic's political crisis and showed a rift among opposition leaders, one of whom fought bravely to stop the violence, while others condemned the events from afar. (Photo by Evgeny Feldman/AP Photo)

Protesters shield themselves as police beat them with sticks during a violent demonstration near the India Gate against a gang rape and brutal beating of a 23-year-old student on a bus last week, in New Delhi, India, December 23, 2012. The attack last Sunday has sparked days of protests across the country. (Photo by Kevin Frayer/Associated Press)

Passengers wait for a train to depart from the Hankou Railway Station in Wuhan, central China's Hubei province, Friday January 13, 2017. Officials expect that Chinese travelers will make almost 3 billion trips during the holiday travel rush that starts runs through Feb. 21. These trips include intercity flights, trains and local bus rides to villages for China's 1.4 billion people. (Photo by Chinatopix via AP Photo)