Armed policemen jump off a truck before they start to walk toward Tangjiashan quake lake in Beichuan county, southwest China's Sichuan Province, May 25, 2008. Armed police troop treked to the quake lake that poses a threat to the dam as airdrop can not be performed due to heavy fog.

Armed policemen jump off a truck before they start to walk toward Tangjiashan quake lake in Beichuan county, southwest China's Sichuan Province, May 25, 2008. Armed police troop treked to the quake lake that poses a threat to the dam as airdrop can not be performed due to heavy fog.