UPDATE: Protesters arrested after climbing onto Tony Abbott's Manly electorate office

Four activists protesting the Australian government's detention of asylum seekers have been arrested after climbing onto the roof of Tony Abbott's Sydney electorate office.

The men managed to clamber up onto the roof of the three level building on Sydney Road about 9am and later unfurled a large banner over the building's side that read "Hunger for justice".

It is believed the group are members of the Australia-wide protest group Cross Border Collective and camped out on top of the building to show their solidarity with 15 refugees on a hunger strike in Darwin.

Several police officers, including a negotiator, climbed onto the roof to speak with the group and eventually managed to coax the men off the roof about 11.15am.

It is believed several other protesters were downstairs inside the electorate office.

The four men who had been on the roof were taken to Manly police station. It is unknown if they have been charged.

Cross Border Collective says on its Facebook site the co-ordinated action and campaign, Hunger for Justice, was organised to express solidarity with detainees on Manus Island, Nauru and in detention in Darwin.

One of the protesters, Claire Parfitt, said the protest was to show solidarity with 15 refugees on a hunger strike in Darwin including one man, Martin, who she claimed was close to death.

"We have created this international media spectacle today to expose the torture, abuse, and horrific conditions that are being perpetrated on Manus Island," the group said.

The protest is understood to have been carried out in conjunction with a demonstration on board a Qantas flight at Melbourne airport this morning.

Several passengers refused to sit down, delaying the flight's departure by about 25 minutes in response to the deportation of a Tamil asylum seeker.

The two protests follow an incident last night which saw several protesters interrupt play at the Australian Open.

A similar sign was unfurled and two men ran onto the court during the Andy Murray and Novak Djokovic match.