By Hyunsu Yim, Nicoco Chan, Minwoo Park SEOUL (Reuters) -While South Korean protesters have long employed songs, dances and chants, customised light sticks popular with K-pop fans have emerged as an effective new tool for demonstrators calling for the impeachment of President Yoon Suk Yeol.

Tens of thousands of South Koreans poured onto the streets Saturday, in the largest protest yet over President Yoon Suk Yeol's ill-fated effort to impose martial law on the country was thwarted.

“Impeach, impeach. Impeach Yoon Suk Yeol,” protesters chanted to the beat of K-pop group aespa's latest techno track "Whiplash". Videos of synchronized chanting and light stick movements in unison at the protests have gone viral on social media along with flags carrying messages and memes from mainly younger demonstrators.