Media playback is unsupported on your device Media caption Thousands rallied in Seoul calling for the president to step down

South Korean prosecutors have issued arrest warrants for two former aides of President Park Geun-hye as part of an investigation into government corruption.

Ms Park's former senior secretary for policy An Chong-bum, and private secretary Jung Ho-sung, are wanted in relation to charges of fraud and abuse of power.

The president has so far refused to resign over the scandal.

She apologised on TV on Friday.

Appearing close to tears in a televised address, Ms Park admitted that she made an error in allowing her friend Choi Soon-sil inappropriate access to government policy-making.

But she denied allowing cultish rituals to be performed in the presidential palace.

Ms Choi, the daughter of a cult leader, is suspected of using their friendship to solicit donations to a non-profit fund she controlled. She is in detention facing charges.

Image copyright Getty Images Image caption South Korean President Park Geun-hye apologised over the scandal in a televised address

The corruption scandal, which threatens to engulf Ms Park's leadership, has left the president with an approval rating of just 5%, the lowest ever for a sitting South Korean president.

Tens of thousands of South Koreans have been protesting in the streets of the capital, Seoul, demanding her resignation.

Image copyright Getty Images Image caption South Koreans took to the streets of Seoul to demand that Ms Park step down

The main opposition party, which said the president's apology on Friday lacked sincerity, also called on Ms Park to step back from state affairs.

Ms Park became her country's first female president when she was elected in a close-run contest in December 2012.

Ms Choi is the daughter of Choi Tae-min, a shadowy quasi-religious leader who was closely linked to Ms Park's father, then-President Park Chung-hee.