Elizabeth Somers, 9, and her Korean friend Su Yon, 12, picked up rubbish around West Lake on April 23 morning instead of playing around the home like other children.

Wearing masks and gloves, they joined about 400 people collecting plastic and other rubbish around the lake. They were volunteers for the Hanoi Environmental Group, in collaboration with non-governmental organisations, companies and individuals, who have organised activities to protect the environment in Hanoi .

"We were here at 9.30am and we're in charge of tidying up this road, including the garden," Elizabeth said. "We have the same environmentally friendly activities at our UNIS school."

Another volunteer, Gerd Koblitz, who came to Vietnam to work as an English teacher, said the campaign will help improve people's awareness of keeping the environment green and clean.

"Environmental protection is our responsibility. If someone dumps waste and assumes that there'll be someone else to pick up their litter, they are wrong. What will happen if everybody has the same thought?" Koblitz said.

He said people in his country, Australia , started the anti-litter movement in the 1970s and most got involved.

Ben Minot, one of the group's founders, said it was the result of initiatives from Hanoi 's expatriate community to preserve Hanoi 's environment.

The group had no office, no leader and no profit, he said.

"All we do is to mobilise expats and Hanoians to gather here and make Hanoi cleaner and cleaner," Minot said.

"This is the second time we've held the campaign. Our Earth Day actions today drew double the number of people last year to clean up West Lake and plant trees," Minot said.

"The volunteers have been divided into groups in charge of different areas around the lake.

"We're not going to go into the lake to clean the water or to clean all around the lake so it will still have a pollution problem and mass fish deaths.

"But we hope our actions will stop people from continuing to dump into the lake," he said.

"Awareness is important and action will create awareness."

Minot, who came with his wife to Hanoi several years ago, said anyone could join the group and tidy up the city instead of complaining about it.

The group said that more initiatives will be launched soon to create a greener Hanoi , including the 26 Degree programme, which will urge people to keep their air conditioners above 26 degree Celcius.

This willreduce energy consumption and the amount of heat pumped into the street and reduce the impact on the environment, the group said.

They have also produced grocery bags using fair-trade labour practices and eco-friendly materials for use instead of plastic bags.

The group was established in April last year with support from the Italian and Australian embassies, companies and individuals.

The first clean-up programme was held last year with the participation of about 170./.