Thousands of people have marched in Northern Ireland today, to call for the introduction of same-sex marriage.

Beginning at Writer’s Square and converging at Belfast City Hall, the rally attracted thousands of people.

Image: Twitter (@KHayden2412)

Images of the thousands of attendees holding rainbow flags began to appear on social media.

Amnesty NI tweeted earlier today to say that 10,000 people had marched, but later said more and more had joined, and that there were at least 20,000 people demonstrating.

Correction. Twenty thousand March for #MarriageEquality in Belfast! And still they come… pic.twitter.com/D7Ljl3gjGn — Amnesty Int'l NI (@AmnestyNI) June 13, 2015

The Assembly in Northern Ireland has debated the issue of same-sex marriage, but it has been blocked each time.

Image: Twitter (Amnesty NI)

The march today was arranged by the Irish Congress of Tradue Unions (ICTU), Amnesty International and the Rainbow Project.

In a statement, the ICTU said: “In 2005, history was made when Northern Ireland became the first place in the UK to hold a civil partnership.

Image: Twitter

“Ten years later, with every other part of these islands recognising marriage equality, citizens in Northern Ireland have effectively been left behind.”

Image: Twitter (@Wattie187)