Anti-war rallies and demonstrations, organised by the Stop the War Coalition were held in London, Edinburgh, Portsmouth and other cities in Britain, calling for an end to the renewed conflicts in Gaza, Xinhua reported.
In London, thousands of demonstrators assembled Saturday at the BBC headquarters in Portland Place and marched to the US Embassy.
Raising anti-war banners and placards, the protestors chanted slogans: "Free Palestine", "End the siege of Gaza", "Stop the killings", "Today we are all Palestinians".
A 72-hour ceasefire in the Gaza Strip brokered by Egypt ended Friday without reaching to an agreement between Israel and Hamas-led militants in Gaza.
The toll of Palestinians killed in the recent conflicts has escalated to 1,922, of whom 1,407 are civilians, while more than 9,500 people have been injured.