According to the tabloid The Sun, the seven-second clip was posted on Instagram by staff relaxing at a ‘teambuilding’ exercise at a Karting track in Birmingham in central England, before being deleted.

In the video, five people in black jumpsuits and balaclava helmets stand behind a man kneeling in an orange jumpsuit. One holds a coat-hanger to the kneeling man’s throat as if preparing to slit it, while others shout “Allahu Akhbar!” (‘God is great!’).

The bank confirmed late Monday it had fired the people responsible, saying: “We do not tolerate inappropriate behaviour. As soon as The Sun brought this video to our attention we took the decision to sack the individuals involved. This is an abhorrent video and HSBC would like to apologise for any offence caused.”

The video is brutally reminiscent of others filmed by Islamic State showing the executions of hostages such as British aid workers Alan Henning and David Haines.

HSBC has been stumbling from one PR disaster to another in recent years, paying billions of dollars in fines for helping Mexican drug cartels launder money, rigging markets for foreign exchange and interest rates, mis-selling financial products in the U.K. and U.S.. It has also faced allegations that it helped thousand of customers to evade taxes through its private bank in Switzerland.

The bank’s management is looking at relocating its headquarters back to Hong Kong, ostensibly to avoid the high costs of a levy imposed by the U.K. government on bank balance sheets. The levy was introduced after the financial crisis and has been raised repeatedly since.