PHILADELPHIA – Protests outside the Democratic National Convention have intensified.

Last night the Secret Service arrested four people as some protesters tried to break through the barricades surrounding the Wells Fargo Center.

It started as an angry but mostly peaceful protest by the group Black Lives Matter. Hundreds of activists marched for miles down Broad Street to the site of the convention, trailed by Philadelphia police. When they reached the arena, many just kept going, shoving their way through police lines and climbing the high fence around the convention.

That was enough for the Secret Service, who moved in to make the convention’s first arrests.

Four protesters were charged with entering a secure federal facility. They were held to await an appearance before a federal judge this afternoon and are expected to be released tonight.

Philadelphia police point out they’ve made zero arrests so far,and hope that Bernie Sanders’ show of support for Hillary Clinton takes the wind out of protesters’ sails.