Seoul - South Korea stepped up security Saturday ahead of the arrival of the Olympic torch which will be carried through the streets of the capital Seoul on Sunday.

Around 8,000 police backed by police helicopters will be mobilized to guard the torch during a 20-kilometre relay, KBS television reported quoting police officials.

Authorities fear clashes between pro-Chinese demonstrators and human rights activists, as well as protests against the deportation by China of North Korean refugees.

"We will take stern measures if protesters disrupt the torch relay," an official at the National Police Agency was quoted as saying by South Korea's Yonhap news agency.

Hundreds of Chinese residents meanwhile plan to welcome the Olympic flame, Yonhap reported.

The torch arrives after a one-day relay in Japan. The torch relay has been accompanied by protests on several stages around the world against China's crackdown on pro-independence demonstrators in Tibet.

The Olympic flame will then head to Pyongyang, the capital of North Korea, on Sunday night. (dpa)