Riot police file past a pile of manure at a farm during a demonstration in Garmisch-Partenkirchen, southern GermanyJune 7, 2015. [Photo/Agencies]

To ensure the safety of the leaders, some 17,000 police officers are reportedly on duty in Bavaria during the summit, and a 10-mile long wire fence has been erected around the G7 venue. Journalists reported that they were being kept at arm's length from where the talks take place.

Anti-G7 demonstrations have continued on Sunday in and around Garmisch-Partenkirchen. Protestors were sitting on the road leading to the luxury resort Elmau, trying to block the way to the meeting venue. Several were taken into custody by the police, according to media reports.

The G7, an informal forum for major industrialized nations to discuss global issues, has been facing a lot of criticism. Opponents say world leaders have repeatedly failed to take decisive actions on the most pressing global issues. The group is also accused of being "a self-interested group for the elite" and lacking of transparency.

"We are here because we want to get across the message to the G7 that the world outside is watching...We think they are not doing enough," said a protester group to Xinhua.

The "One" campaign, which calls for an end of extreme poverty in the world, has held a demonstration outside the G7 media center, about 10 km from the Schloss Elmau, demanding that "we want more than hot air."

"You know in English the expression 'hot air' can mean empty promises...when it's all talks, and no action," Adrian Lovett, the group's Europe Executive Director said.

"We know that there will be a lot of words at this summit... That's fine as long as there's real action behind it. We are looking for more than 'hot air'. We are looking for real action from this summit." he added.