More than 100 university teachers and students from Hong Kong and the Chinese mainland continued their field survey in the northwestern Gansu Province on Friday after a dramatic night when more than half of them were reported as "missing".

The group, including 45 from the University of Hong Kong and the Chinese University of Hong Kong, expect to arrive in Zhangye City later on Friday, said Wang Naiang, the team's leader from Lanzhou University.

About 80 students and teachers were reported missing on Thursday night when they lost contact with their teammates in Menyuan Hui Autonomous County of the neighboring Qinghai Province.

"We were 15 minutes late when we returned from a field survey in torrential rain," said Wang, who was one of the "missing". "Communication was bad and we were unable to get in touch with our teammates via cell phone."

The teacher who was waiting for them panicked and drove to the local police station for help, a trip that took about two hours, said Wang.

The incident caused an alarm in the county and dozens of local public security officials joined the search.

On behalf of his team, Wang expressed thanks for the officials and reporters who tried to help them Thursday night. "Thank you all for your attention. We are perfectly safe now," he said in a telephone interview with Xinhua Friday.

The 112-member team left Lanzhou, Gansu's provincial capital, on Sunday for the 12-day survey to study geology, vegetation, environment changes, resource exploitation and cultural heritage sites along the ancient Silk Road.

The trip will last until July 24.

(Xinhua News Agency July 18, 2009)