Some expatriates and local people used last Sunday to clean a seriously polluted canal on Hanoi's Nguyen Khang Street, surprising the local authorities.

The photos immediately attracted thousands of views and comments from local people, all expressing surprise and thanks to what they did.

Answering Lao Dong Newspaper on May 6 about their activities, chairman of Yen Hoa Ward, Hoang Trung Kien, said he had just been heard about their work.

"I heard that they come from an environmental group," Kien said. We didn't know about their plan before. This canal was recently featured on local newspapers due to its serious pollution. Maybe the group knew about it and came to help local people."

Kien added that local authorities had also cleaned the canal a short time before the group arrived.

 The cannal (before it was cleaned) was recently featured on local newspaper due to serious pollution

A source told Lao Dong Newspaper that the group came from the Keep Hanoi Clean environmental group on Facebook founded and run by an American.