Why did HSBC close Gaza charity account?

It seems very strange that HSBC has written to a British charity, Ummah Welfare Trust, (dedicated to relieving suffering in Gaza, and elsewhere) informing it that it intends to close its accounts as the charity now falls outside the banks’ “risk appetite”. HSBC is the only foreign bank operating in Israel that provides private banking accounts. I wonder if this fact has anything to do with their risk appetite – sod humanitarian aid.

Here is an article in RT on the subject, which quotes me.

The charity accepts donations here