The tranquil waters of Hangzhou's West Lake have inspired Chinese poets and painters for centuries. On Sunday the serenity was imposed by force as authorities deployed a vast security operation for the G20 summit.

The throngs of tourists who usually crowd the shores of the island-dotted lake were absent and the surrounding roads closed off -- except for police vehicles and the occasional motorcade of black luxury cars emblazoned with national flags.

But when a handful of locals living in the immediate area were allowed past the cordon, they took advantage of the empty streets to embrace an untraditional pursuit: road-top selfies.

Young people sat on the tarmac taking pictures of themselves, while others made star-shaped poses with their arms and legs for friends to snap them.

The streets spruced up for the benefit of leaders, trees glowing with artificial lights, made an ideal backdrop.

State media say that more than two million people out of a population of some nine million have left Hangzhou, taking advantage of a paid holidays which local firms have been ordered to give employees.

Local reports said so many people visited Huangshan, a mountain range in the next province where Hangzhou residents were given free tickets, that hillside passes turned into human traffic jams.

Wealthier residents of apartments near the G20 venue were offered sizeable cash incentives to leave their homes.

But treatment was apparently harsher for Hangzhou's vast population of migrant workers, with several saying they were ordered to shut their small businesses without compensation.

"We were ordered to close our restaurant, so I've gone back to my hometown in Sichuan," said a woman surnamed Zhou whom AFP reached by telephone. "We are losing money."

"At the beginning we were told about compensation but it didn't happen," she added.

Security is generally tight for G20 summits wherever they are held, as they are a magnet for protesters seeking a global audience for their cause.

State media say that since December one million people have been mobilised as "volunteers".

Red-armbanded personnel stand, squat or sit on street corners and inside apartment compounds throughout Hangzhou, apparently with little to do.

A policeman prevented an AFP reporter from taking photos of the guards in one compound, and several volunteers said they needed authorisation to speak to foreign media.

"I work for a state-owned enterprise, who have organised this volunteer work," said one armbanded worker surnamed Wang, sitting on a stool near a bus stop.

"My job is to look our for people who get off the bus with dangerous items such as knives."