German police stepped up security checks Friday across a broad radius surrounding the venue for a Group of Seven summit at the weekend, as activists warmed up for protests against the gathering.

More than 22,000 police were deployed throughout the southern state of Bavaria, where Chancellor Angela Merkel will welcome leaders on Sunday, DPA news agency reported.

Security forces set up checkpoints as far away as the state capital Munich, 100 kilometres (60 miles) north of the meeting’s venue, the luxury hotel, Elmau castle.

A police spokeswoman said suspicious vehicles, including those carrying large groups of protesters, could be stopped and searched, “which could also lead to traffic jams”.

As environmentalists hung a banner demanding concrete action on global warming atop Germany’s highest mountain peak, hundreds of summit opponents rallied and set up camp in the valley below in Garmisch-Partenkirchen.

“The water is up to here,” the banner at the nearly 3,000-metre (9,800-feet) high Zugspitze mountain read. “The world expects action and not just hot air.”

Protesters burned a mock-up tank labelled “Yemen”, “Somalia” and “Afghanistan” and carried a banner reading “Fight G7 — Against War and Militarisation”.

On Thursday, more than 30,000 people in Munich kicked off protests against the G7.

Environmentalists, opposition parties and anti-globalisation activists rallied under the banner “Stop TTIP – Save the Climate – Fight Poverty”.

The TTIP or Transatlantic Trade and Investment Partnership is a proposed treaty currently under negotiation between the US and Europe.

The two-day summit is expected to cover international trade, the push for a UN climate accord, public health, poverty reduction and global security crises, among other issues.