China has sent a large number of soldiers and paratroopers to Tibet after the violent protests in Lhasa. This army convoy was on G318, the main road into Tibet from Sichuan province.

On Wednesday alone, BBC reporters saw more than 400 troop carriers and other vehicles on the main road. The mobilisation is the biggest since the unrest began in Lhasa on 10 March.

This jeep is driving between assembly points in one town. It was seen to clear potential trouble-spots for the military convoys along the way.

Mao Zedong and his Red Army crossed this river during the Long March, pursued by KMT forces. Today's army is moving into ethnic Tibetan areas neighbouring Tibet.

Banners on the trucks say the soldiers are on a "New Mission". The soldiers are armed with pistols, rifles and machine-guns.

Many of the soldiers are likely to be deployed in western Sichuan where Tibetan protests have taken place, or cross this bridge over the Jinsha River into Tibet.