Hundreds of thousands have rallied in South Korea for what is thought to be the largest protests so far demanding President Park Geun-hye steps down.
Ms Park is accused of allowing her friend, Choi Soon-sil, to manipulate power from behind the scenes.
The president has apologised twice on national television, but has so far resisted calls to resign.
Organisers said 1.3 million had gathered in capital Seoul on Saturday night, despite cold weather and snow.
They expect another half a million protesters to turn out in other regions.
However police put the turnout at about 260,000. About 25,000 officers were being deployed in the capital, local media said.
The protests, which began five weeks ago, are the largest in South Korea since pro-democracy demonstrations of the 1980s.
Those attending on Saturday came from a cross-section of South Korean society, with farmers, Buddhist monks and university students all involved.
"I was watching the news and thought this cannot go on - people really want her to step down but she hasn't," one of the protesters, Kwak Bo-youn, told Reuters.
"This is the second time for me to the protests, but the first time for my husband and kids."
The big question - by BBC's Stephen Evans in Seoul
Convoys of farmers have been prevented from taking their tractors into Seoul - but the streets have been packed with people, chanting that President Park Geun-hye should step down.
Apart from the corruption allegations, she has become the focus of discontent over the economy. Farmers, for example, spilled sacks of rice on the road in protest at low rice prices.
Courts have permitted demonstrations up to 200 metres from the presidential palace but only before nightfall.
Tens of thousands of police are deployed, with the full panoply of anti-riot gear.
The question is whether the more militant elements will disperse or try to get to the presidential palace.
Ms Park, whose approval rating has dropped to 5%, apologised earlier this month for putting "too much faith in a personal relationship", and has pledged to co-operate in an official investigation into the scandal.
South Korea's constitution does not allow a sitting president to be prosecuted, and Ms Park has 15 months left in her term.
But now that prosecutors have directly linked her to the scandal, it is possible she could be impeached for breaking the law.
Prosecutors are expected to bring charges against Ms Choi, along with two former presidential aides. She was arrested earlier this month.
Ms Choi is accused of trying to extort huge sums of money from South Korean companies, and suspected of using her friendship with Ms Park to solicit business donations for a non-profit fund she controlled.