South Korea has voted to impeach its acting president Han Duck-soo, two weeks after parliament voted to impeach its President Yoon Suk Yeol.

There were rowdy scenes in the National Assembly after the speaker announced that only 151 votes out of 300 would be needed to pass the impeachment bill, as opposed to the 200 votes required to impeach President Yoon.

Lawmakers from Yoon and Han's PPP ruling party crowded around the speaker's chair in protest and boycotted the vote.

A total of 192 lawmakers voted for Han's impeachment.

Prime Minister Han took over the role after President Yoon was impeached by parliament following his failed attempt to impose martial law on 3 December.

But opposition MPs have accused Han of refusing to appoint judges to Yoon's impeachment trial, effectively stalling proceedings.

Han has agreed to step aside, which means the country's finance minister, Choi Sang-mok, will become acting president.

Jean McKenzie reports from Seoul.