Healthcare activist is detained after a protest to stop the Republican health care bill at Russell Senate Office Building on Capitol Hill in Washington, US, July 10, 2017. [Photo/Agencies]

WASHINGTON - US Capitol police on Monday arrested 80 protesters who demonstrated against a Republican-backed healthcare bill.

Officers arrested 21 people at House office buildings and 59 people at the Senate side of the Capitol building, according to a police statement.

The demonstrations started in the afternoon, and police were called to 13 locations inside the compound in response to calls.

Video images showed the demonstrators chanting slogans and holding up boards that denounced the new healthcare bill.

The police who arrived on the site asked the demonstrators to cease, and those who refused to comply were arrested and will be charged with "crowding, obstructing, or incommoding".

The target of the demonstrations is a healthcare reform bill unveiled by Senate Republicans in June in a step to repeal and replace the Affordable Care Act, also known as Obamacare.

The Republican bill has faced opposition from both Democrats and fellow Republicans. Senate Majority Leader Mitch McConnell was forced to postpone a vote on the bill in late June to seek more support.