Hundreds of thousands of demonstrators gathered in the streets around Taiwan's parliament on Sunday to protest against a trade pact with China.
The rally was part of a nearly two-week-old protest that is challenging the president's policy of moving the democratic island economically closer to China.
Lin Fei-fan, a protest organiser, estimated that 500,000 people had turned out in the biggest demonstration since the movement started.
Crowds dressed in black sat on one blocked boulevard, many carrying plastic or real sunflowers, the symbol of the protest movement, and wearing yellow ribbons that read "Fight for democracy, retract the service trade pact."
Several hundred mainly student protesters have been occupying Taiwan's parliament building since March 18, supported by thousands outside the building.
They are protesting against president Ma Ying-jeou's intention to enact a trade deal that would allow Taiwanese and Chinese service sector companies to open up branches or shops in the other's territory.
On Saturday, Mr Ma gave in to students' demands to increase scrutiny of future pacts signed with China, but refused to withdraw the pact in question, saying it would deeply harm Taiwan's interests.
"I'm not against free trade, but the government should come up with policies to protect local industries before they open the door," said a protester, Philip Lihan, 30, a graphic designer in Taipei originally from Chiayi in southern Taiwan.
"I've been sitting-in near the legislature every day after work until midnight," said Mr Lihan, who added that he had been working with other artists to create murals in support of the protest.