South Korea's ruling party leader said President Yoon Suk Yeol needs to be removed from power for trying to impose martial law, as the government denied reports on Friday it was preparing to issue another martial law declaration.

Yoon shocked the nation - and his own ruling People Power Party - on Tuesday, when he gave the military sweeping emergency powers in order to root out what he called "anti-state forces" and overcome obstructionist political opponents.

He rescinded the declaration about six hours later after parliament, including some members of his party, voted to oppose the decree.

The main opposition Democratic Party has submitted a motion to impeach Yoon and scheduled a vote in parliament for Saturday evening.

Fearing another attempt to declare martial law, opposition lawmakers rotated through parliament's plenary session hall on Friday to block any such attempt, a Democratic Party official said.

Acting Defence Minister Kim Seon-ho said reports there may be another attempt to impose martial law were not true.

Speaking after a meeting of the conservative People Power Party at the parliament on Friday, leader Han Dong-hoon said Yoon had ordered the arrest of prominent politicians.

The presidential office later denied any such order had been given, the Yonhap news agency reported.

Han said earlier there was "a high risk of extreme actions such as this emergency martial law being repeated" while Yoon remained in power, putting the country in "great danger".