Organizers claimed that some 50,000 protesters took part in the demonstration on Sunday, forming a human chain that stretched from Aachen, Germany, to Liege, Belgium, and Maastricht, the Netherlands.

The chain also passed close the Tihange nuclear power plant some 20 kilometers (12.4 miles) southwest of Liege. The Tihange 2 and Doel 3 reactors have been the subject of safety concerns about microcracks in their structures.

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Doel lies in northern Belgium, close to the port city of Antwerp, about halfway between Brussels and Amsterdam. Numerous safety incidents, mostly low-level, have been reported from the two reactors which have each been in operation for more than 30 years.

Protesters who massed in Germany, the Netherlands and Belgium complain they are living with excessive risk

German Environment Minister Barbara Hendricks last year urged Belgium to take the two reactors offline until open safety questions were cleared up. However, the request was dismissed by Belgium's nuclear regulator.

Aachen takes legal action

The city of Aachen and some 100 communities in the border region are currently suing the operators of Tihange 2.

Sunday's demonstration was organized by numerous environmental organizations in all three countries and spearheaded by Belgian actor and director Bouli Lanners. The mayors of Aachen and Cologne also lent their weight to the protest.

"It is the strongest message the region could send," said the administrative head of the Aachen city region, Helmut Etschenberg. "We no longer want to live with the element of uncertainty that is Tihange 2 and we will keep on and on."

As well as demanding the closure of the plant, demonstrators are calling for an end to deliveries of fuel elements to the two power stations from Germany's Lingen nuclear power plant, in the state of Lower Saxony.Such is the level of concern about Belgium's aging reactors in Germany that the state of North Rhine-Westphalia has stocked up with iodine tablets in an effort to limit human exposure to radiation.

rc/sms (dpa, AFP, AP)