In this photo released by China's Xinhua News Agency, torchbearer Ai Fukuhara, a Japanese table tennis star, runs with the torch in Nagano, Japan,26 Apr 2008

The South Korean leg of the Olympic Torch relay is under way in the capital of Seoul under heavy security.

Authorities say more than 8,000 riot police have been deployed to provide security for the relay.

At least two human rights groups have promised to try to disrupt the relay. They want China to stop deporting North Korean refugees, who face stiff punishment or execution for fleeing the north.

The Japanese leg of the relay took place Saturday, with a few demonstrators throwing objects into the torch's path and scuffles between protesters and police. At least one person was detained as the torch made its way through the streets of the northern city of Nagano.

The torch run has been disrupted in other major cities in recent weeks by protesters condemning Chinese human rights practices, especially its forceful suppression of demonstrations in Tibet.