As PPs have stated, at the Gaza demos there are people of many faiths and none. I support Palestine, and I'm a Christian (as are many Palestinians by the way) in fact I'd say there are fewer Muslims than non-Muslims.
The world's a village. The genocide in Gaza is a British issue too, as weapons have been manufactured on British soil, and sold and supplied to Israel. Also, Britain had a massive role in the zionist creation of the state of Israel, due to the Balfour Declaration. In addition, the UK government invaded Iraq, Afghanistan, contributed to the crisis in The Yemen. Not to mention its long history of colonialism worldwide. If you don't want the middle east conflict to be protested about (by either side) then maybe ask the government to stop funding the daily slaughter of innocents in the region?
It's everyone's business honestly.
Many of the material freedoms and privileges you and I, and all of us, enjoy here, are due to the long dark history of slavery and colonialism. Britain gained huge wealth during that time, and still benefits. We're not a wealthy western country by accident. To complain about immigration now is very unfair indeed.