Many local businesses stayed shut on Tuesday morning in Lübeck, the quiet Hanseatic town less than an hour northeast of Hamburg on Germany's Baltic coast. The closures came in anticipation of demonstrations from political and environmental groups against a meeting of the G7 foreign minister.

"I'm a little afraid that there could be the kind of rioting [we saw in Frankfurt last month]," a business owner told northern German public broadcaster NDR as he boarded up his windows.

Despite remaining largely peaceful, "Blockupy" rally of more than 10,000 people in Germany's financial capital made headlines in March when a group of protesters torched security vehicles and clashed with police.

Lübeck authorities sealed off much of the city for the two-day talks. On Monday evening, they reported finding cobblestones hidden in trash cans near the city's famous Holsten Gate.

Some 3,500 police officers were deployed to the area to monitor three security areas and to ensure peaceful protests.

A vigil held the previous evening drew roughly 500 people, but thousands more were anticipated to flock to the Hanseatic city for the foreign ministers' meeting on Tuesday.

Demonstrations remained peaceful on Monday

The top diplomats from France, the United Kingdom, Italy, Japan, the US, Canada and host nation, Germany, were to convene at 3 p.m. local time (1300 UTC). The EU High Representative, Federica Mogherini, was also scheduled to attend.

Conflicts in Ukraine and the Middle East, as well other geopolitical risks, such as the fight against Ebola and action against climate change were to top the agenda.

Lübeck was founded in the 12th century. Its high gothic architecture and historic buildings, such as its historic City Hall, are protected earned the status UNESCO world heritage site in 1987.

kms/jil (AFP, dpa)