Actress Hannah held over protest

Hannah is a keen environmentalist and regularly campaigns

Actress Daryl Hannah has been arrested after protesting against mountain top mining in West Virginia.

The 48-year-old was among 31 people arrested after they blocked a road near a coal processing plant.

The protestors had marched to the plant and attempted to gain entry after a nearby rally. When miners blocked their way, the demonstrators sat in the road.

Police said all 31 were released after being cautioned for impeding traffic and obstructing an officer.

Mountain top mining involves blasting ridge tops to expose coal seams. While mine operators are required to return the mountain to its approximate original shape, excess material is used to fill valleys, which can bury streams and affect the local ecology.

"It's not necessary," Hannah said before she was arrested.

"If you do it wisely, there are ways to use renewables. It's realistic for everybody."

Hannah is a keen environmentalist and regularly speaks around the US about the use of biodiesel as an alternative source of fuel.

She was previously arrested in 2006 after chaining herself to a walnut tree in a Los Angeles urban community garden, during a protest against the site's planned demolition to make way for a warehouse.

Nasa climate scientist Dr James Hansen was also among those arrested in West Virginia on Tuesday.

Another woman - who was among a crowd of mining industry supporters - was charged with battery, State Police Sgt Michael Baylous said.