Taiwan has become the first country in Asia to legalise same-sex marriage.

The landmark bill was passed by 66 votes to 27 following a heated debate over marriage equality that has divided the self-ruled island.

Thousands of supporters of same-sex marriage gathered outside parliament in the capital Taipei.

Ahead of the vote, president Tsai Ing-wen posted on Twitter: "Today, we have a chance to make history and show the world that progressive values can take root in an East Asian society."

Shiau Hong-chi, professor of gender studies and communications management at Shih-Hsin University in Taiwan, said: "It's a breakthrough, I have to say so. I could not imagine that could happen in just a few years."


Image: Same-sex marriage supporters take part in a rally ahead of the vote

Phil Robertson, deputy Asia director for Human Rights Watch, wrote on Twitter: "#Taiwan's action today should sound a clarion call, kicking off a larger movement across #Asia to ensure equality for LGBT people and pro-active protection of their rights by governments throughout the region."

In 2017, the democratic island's constitutional court declared same-sex couples had the right to legally marry, and set a deadline of 24 May, 2019, for the law to be formalised.

Taiwan's acceptance of gay and lesbian relationships began in the 1990s when leaders in today's ruling Democratic Progressive Party championed the cause to help it stand out in Asia as an open society.

Vietnam lifted a ban on same-sex marriage in 2015, however that is seen as purely ceremonial as they are not offered the same legal protections available to opposite-sex couples.

Although claimed by China as its own territory, Taiwan is a self-governing democracy with a vibrant civil society.