Rival protests over South Korea's impeached President Yoon held in Seoul

Demonstrators supporting and opposing South Korean President Yoon Suk Yeol held rival protests several hundred metres apart in Seoul on Saturday, a week after he was impeached over his short-lived declaration of martial law.

Yoon's presidential powers are suspended but he remains in office. He has not complied with various summonses by authorities investigating whether martial law, which he declared late on Dec. 3 and rescinded hours later, constituted insurrection.

He has also not responded to attempts to contact him by the Constitutional Court, which decides whether to remove him from office or restore his presidential powers. The court plans to hold its first preparatory hearing on Friday.

Saturday's pro- and anti-Yoon protests were held in Gwanghwamun in the heart of the capital. There were no clashes as of 4 pm (0700 GMT).

Tens of thousands of anti-Yoon protesters, dominated by people in their 20s and 30s, gathered around 3 pm, waving K-Pop light sticks and signs with sayings such as "Arrest! Imprison! Insurrection chief Yoon Suk Yeol" to catchy K-pop tunes.

"I wanted to ask Yoon how he could do this to a democracy in the 21st century, and I think if he really has a conscience, he should step down," said 27-year-old Cho Sung-hyo.

Several thousand pro-Yoon protesters, chiefly older and more conservative people opposing Yoon's removal and supporting the a restoration of his powers, had gathered since around midday.

"These rigged (parliamentary) elections eat away at this country, and at the core are socialist communist powers, so about 10 of us came together and said the same thing - we absolutely oppose impeachment," said Lee Young-su, a 62-year-old businessman.

Yoon had cited claims of election hacking and "anti-state" pro-North Korean sympathisers as justification for imposing the martial law, which the National Election Commission has denied.