Protesters hold candles during an anti-government rally in central Seoul on November 19, 2016, aimed at forcing South Korean President Park Geun-Hye to resign over a corruption scandal. [Photo/Agencies]

Opposition parties may launch a procedure of impeaching President Park as hundreds of thousands of protesters on Saturday night demanded Park's resignation and even an immediate custody investigation into the president.

The impeachment, however, would be a tough option to select as opposition lawmakers are required to win at least 200 ayes from the 300 parliamentary seats to approve an impeachment bill. The ruling Saenuri Party has over 120 seats in the National Assembly.

Choi Soon-sil, Park's decades-long friend, was indicted by prosecutors for abuse of power, coercion, attempted coercer and attempted fraud. Ahn Jong-beom, former senior presidential secretary on policy coordination, was charged for abuse of power, coercer and attempted coercion.

Choi is suspected of asking President Park to order Ahn to pressure 53 conglomerates into donating tens of millions of US dollars to two nonprofit foundations presumably controlled by Choi.

Jeong Ho-seong, former presidential secretary, was indicted for leakage of official secrets. Jeong is dubbed as one of "three knobs of a door" that leads directly into President Park as he aided her for almost two decades.

Park is suspected of ordering Jeong to bring presidential documents on confidential defense and diplomatic affairs to Choi in a bid to get recommendations from her longtime friend, who is a private citizen having no public position.