People other than rescuers might have difficulty entering northwest China's quake zone, according to a government directive released Sunday.

The directive aims to let trained rescuers do their job in an effective and orderly manner.

"To show support for the rehabilitation, volunteers, travellers, and other people who are not directly involved in the emergency rescue" were advised not to enter the quake zone, said the earthquake rescue headquarters in the directive labeled no. 39.

A 7.1-magnitude quake struck the Tibetan Autonomous Prefecture of Yushu Wednesday. At least 1,706 were killed in the quake, and 12,128 others were injured, according to Sunday's official tally.

Made of wood and mud, most houses in the area collapsed or were on the verge of collapse after the quake.

Tens of thousands of people need to be relocated.

Since Wednesday, thousands of soldiers and officers, armed police, medical workers and other trained rescuers have been working in the quake zone, an otherwise isolated region on account of its remoteness and harsh conditions.

"The hardest-hit town of Gyegu sits at 3,700 meters above sea level and there is not much space. At present a flood of individuals and vehicles are entering the quake zone, adding extra difficulties to the rescue and relocation efforts," it said.

"Aftershocks may occur, and traffic conditions are difficult. The quake zone can not accommodate more people," it added.

The directive also orders all levels of government in Qinghai not to organize groups of sympathizers to enter the quake zone to console quake victims.

The Ministry of Public Security also advised the public not to drive into the quake zone in a bid to reduce traffic pressure there.

Roads in Gyegu are now overloaded. Ten times more vehicles are driving into this remote mountainous town than it can take, explained the ministry in an advisory. "The normal vehicle flow is around 3,000 cars a day; now the number is over 30,000."

Hundreds of police have been sent to various check-points to ensure traffic in and out of Gyegu is smooth.