Altitude sickness poses the biggest challenge for rescuers from the military and armed police in their quake-relief efforts, a senior military officer said Tuesday.

Wang Zhenguo, an officer with the Yushu quake-relief headquarters of the Chinese People's Liberation Army (PLA) and armed police, said at a press conference that no casualty had been reported among the quake-relief soldiers and armed police so far despite the difficulties.

Soldiers from the PLA and armed police have rescued more than 1,560 people and gave medical aid to more than 20,000 injured in the quake zone as of 10:00 PM Monday, said Huang Xueping, spokesman with the Ministry of National Defense, at the same press conference.

Huang said that nearly 12,800 soldiers and armed police had been sent to the quake zone to relieve the disaster as of 10:00 PM Monday.

Thirteen medical teams and 89 quake-relief aircraft from the PLA and armed police had been dispatched to the quake zone, he said, adding rescuers from the military and armed police had also transported 5,200 tonnes of tents, food and other relief material.

(Xinhua News Agency April 20, 2010)