Washington, Apr 30 (IANS): Hundreds of demonstrators descended on the California Republican Convention to protest against party front-runner Donald Trump ahead of his speech.

Protesters -- some of whom wore bandanas over their faces and carried Mexican flags -- blocked off the road in front of the Hyatt Regency in Burlingame city on Friday, forcing the Republican front-runner's motorcade to pull over along a concrete median outside the hotel's back entrance, CNN reported.

Trump and his entourage got out and walked into the building.

"That was not the easiest entrance I've ever made," Trump said once he began speaking at the convention, adding, "it felt like I was crossing the border".

At one point before Trump arrived, about two dozen protesters tried to rush barriers near the hotel. Police officers then rushed to the building's doors, successfully blocking the protesters from getting in.

Some of the doors' handles were handcuffed from the inside so they could not be forced open.

Several physical altercations, including shoving, could be seen between protesters and police officers, who were using batons to push them back.

After Trump arrived, protesters took down a barrier and flooded the entrance outside the hotel, where police again blocked them from entering. They chanted, "Get him out".

Protesters have disrupted Trump's rallies across the country for months, but have rarely escalated into mass street demonstrations. Many protests have focused on Trump's rhetoric on illegal immigration.

Friday's protests follow a rowdy scene Thursday night outside Trump's rally in Costa Mesa, California, where several scuffles broke out between protesters and Trump supporters.

At least one police car was damaged and one Trump supporter was visibly bloodied after being punched in the face.

About 20 people were arrested Thursday night, police said.