Police were bracing Sunday for demonstrations supporting Israel's military offensive in the Gaza Strip after a pro-Palestinian rally in London ended in violence, afp reported.
Police made 24 arrests after protesters Saturday tried to force entry to gates leading to the Israeli embassy.
A group of about 200 demonstrators hurled sticks and stones at riot police and were forced back by officers on horseback.
Protesters hurled a crash barrier through the window of a coffee shop and other shopfronts were damaged in the Kensington area.
The Met's Commander Bob Broadhurst said a "hard core" of protesters had set out "to deliberately confront and antagonise police".
The clashes came after between 15,000 and 20,000 people, according to police, marched from Hyde Park through central London before a smaller group went on to the Israeli embassy.
It was the second time in eight days that protest organisers Stop the War Coalition had attracted substantial crowds to London in support of the Palestinian cause.
Demonstrators carried placards reading "Stop the Holocaust in Gaza", "Gaza -- stop the massacre", "A salute to the gallant fighters of Hamas" and "Jews against the war on Gaza."
In Edinburgh, organisers said 10,000 people attended a rally Saturday, where around 300 shoes and red paint were hurled at the US consulate.
On Sunday, it will be the turn of pro-Israeli demonstrators to take to the streets of London.
The "Peace in Israel, Peace in Gaza" rally in Trafalgar Square has been organised by British Jewish community organisations to show solidarity with the Jewish state.
A pro-Israeli rally is also due to take place in Manchester.
Israel pressed ahead with its air and ground assault in Gaza on Sunday as the death toll in the 16-day-old war passed 850 and Hamas vowed it would never negotiate a ceasefire while "under fire."
