Police in Nanjing, Jiangsu province, and Golmud, Qinghai province, are working with professional rescue workers to search for a college student reported missing for 19 days as of Sunday.

The student, Huang Yumeng, 24, is a senior at Nanjing University of Aeronautics and Astronautics. She failed to graduate this year before traveling to Golmud alone.

Police in Nanjing's Jiangning district confirmed that Huang arrived in Golmud from Nanjing, about 2,700 kilometers away, on July 5 by train. She took a taxi on July 7 to Hoh Xil, a remote nature reserve that covers 4.5 million hectares of the Qinghai-Tibet Plateau.

Huang had contacted friends on WeChat that day before her cellphone was powered off. She told them she had bought many gifts for them. She also told the taxi driver that she would stay in a tent that she carried with her to Hoh Xil.

One of Huang's teacher's reported her missing on July 8.

Police discovered that Huang had visited many places of interest in Golmud before July 13. On that day, she showed her ID card at a toll station on a road connecting Golmud to the Tibet autonomous region. Since then, there has been no trace of her.

"Three rescue teams are waiting for orders to search for her in Tibet, Qinghai and Xinjiang," said Cai Chao, chief of Lantian National Rescue Troopers, adding that updated information is needed for a rescue attempt.

"Each team has more than 10 members. They will search the vast depopulated areas as soon as they know the direction she might have gone."

Ma Youquan, a Qinghai resident, said no one should travel alone to the depopulated areas of the Qinghai-Tibet plateau because most of them had low temperatures at night, no cellular signal coverage and many kinds of wild animals.

"Even people with outdoor adventure experience dare not explore the depopulated areas without enough preparation," Ma said. "I hope that she's still fine."