As authorities in Hangzhou, Zhejiang Province, prepare to host the G20 summit this weekend, China’s security apparatus has shifted into high gear, with as many as 100 people preemptively detained and many others ordered to skip town for a few days. Potential troublemakers from China's peripheries are also being told to keep out.

Government authorities worldwide fear that various groups may attempt to use large gatherings of world leaders, such as the G20, to draw attention to their cause, whether they are environmental, religious, or political.

Particularly sensitive to any disturbance, the Chinese government is not taking any chances. Representatives from several European charities have been unable to obtain accreditation for the event, AFP reports. Dozens of Chinese have reportedly been detained, and several others have been compelled to travel outside the city during the Sept. 4-5 summit.

Local hotels have also tightened security and are refusing to entertain clients from Xinjiang, home of the ethnic — and persecuted — Uighur minority, which Beijing has accused of orchestrating several attacks across China in recent years.

At least one hotel, the Jinjiang, is even refusing to take in patrons from Hong Kong and Taiwan during the summit.

"We do not entertain clients from Xinjiang, Hong Kong or Taiwan," a receptionist at the hotel told AFP. “After the G20 we can host them.”

Hong Kong’s Legislative Council election will be held on Sept. 4, with several localization candidates seeking to defy the pro-Beijing establishment in the increasingly restive territory. Meanwhile, relations with Taiwan have also become more tenuous following the election of the Democratic Progressive Party’s (DPP) Tsai Ing-wen (蔡英文) in the Jan. 16 elections. Beijing has reacted to her government’s refusal to adopt language on “one China” that it has been insisting upon by suspending some communication channels with Taiwan, where support for unification with China is at an all-time low. Several Taiwanese, particularly individuals associated with the DPP, have been denied entry visas into Hong Kong in recent months.