On October 20, 1959, three Indian border patrol officers crossed the Kongka Pass to the south of the empty Kazan Pass in the northwestern part of Tibet. They were warned by Chinese border guards, but the Indians ignored their warning. The border guards then detained the Indians. The next day, on October 21, an Indian patrol consisting of 70 border patrol officers entered the same area to search for the men who were declared missing, but were ambushed by the Chinese, who were well-entrenched and firing from high positions. The Indians scrambled for cover and returned fire, killing a Chinese soldier, Wu Guoqing. The remaining 13 members of the Chinese patrol team led by squad leader Wenjie then responded. The Chinese counterattacked, forcing them to retreat. The battle ended with nine Indian border patrol officers dead, three others wounded, and seven captured by the Chinese.