The Information and Communication Technologies Authority, responsible for regulating the internet, announced the block early on Friday without providing a reason.

However, the government-aligned Sabah newspaper reported that the block was in response to Instagram removing posts by Turkish users expressing condolences over the killing of Hama political leader Ismail Haniyeh.

This move follows criticism from Fahrettin Altun, the presidential communications director and aide to President Recep Tayyip Erdogan, who condemned the Meta-owned platform for preventing Turkish users from posting messages of condolence for Haniyeh.

Unlike its Western allies, Turkey does not classify Hamas as a terrorist organisation. President Erdogan, a vocal critic of Israel's military actions in Gaza, has described Hamas as "liberation fighters."

Friday has been declared a day of mourning for Haniyeh in Turkey, with flags being flown at half-mast.

Turkey has a history of censoring social media and websites. According to the Freedom of Expression Association, a non-profit organisation of lawyers and human rights activists, hundreds of thousands of domains have been blocked since 2022.

YouTube was also blocked in Turkey from 2007 to 2010.