(Yicai Global) Aug. 9 -- Roads to Jiuzhaigou are heavily congested after last night's magnitude 7.0 earthquake, and rescue teams from the seismological bureau of Sichuan province have not yet reached the quake-stricken area.

Private drones now appear to pose a threat to air traffic control, and may obstruct rescuers' air passage.

Apart from road traffic, air traffic has also been affected, said Jiang Xiaolin, head of emergency rescue service department of the seismological bureau, told Yicai Global in an interview earlier today. The bureau is contacting the air force to increase air transport capacity, he added. Limited space between the mountains and survey drones have hampered air traffic in the area. Worse, the air force has also detected private drones illegally flying above the region, and is trying to suppress them.

Jiang appealed to the public not to operate any drones in the disaster-stricken area without leave, as they may block air passage for rescue forces.

Roads in the area are badly congested, and the government cannot guarantee the evacuation of all tourists by today. Large quantities of relief supplies and many rescue teams are still waiting to enter the disaster zone.