Hundreds of supporters of Donald Trump and protestors clashed outside an election rally of the presumptive Republican presidential nominee in San Diego in the United States.

People from both sides screamed at each other and threw water bottles, as the police tried to control the situation, firing pepper-balls.

The clash between pro and anti-Trump groups occurred after the Republican leader ended his speech in San Diego in the western California state on Friday.

Police were deployed in riot gear as the billionaire from New York addressed a massive rally at a convention centre.