Baku, May 3, AZERTAC At least 20 people were killed and 21 others were injured Friday in a bus accident on the Pakistan-China highway, according to Anadolu Agency.The victims were aboard a passenger bus that fell into a ravine on the Karakoram Highway in Chilas area of the Diamer district of the northern Gilgit-Baltistan region, said Faizullah Firaq, spokesperson for Gilgit-Baltistan chief minister.The Karakoram Highway connects the South Asian nation with China at the Khunjerab Pass in Gilgit-Baltistan."The accident occurred at around 05.30 a.m. (0030GMT) as the driver lost control over the bus which fell into a ravine," Firaq told Anadolu over the phone.He added that the injured were shifted to Chilas Hospital, while four of the critically injured passengers were taken to Gilgit by an army helicopter.Last year in December, at least eight people, including two soldiers, were killed and 26 others injured in a shooting on a passenger bus in the same Chilas area.