The party congress of the right-wing Alternative für Deutschland (AfD) in the German city of Stuttgart started on Saturday after a one-hour delay, amid protests by about 1,000 left-wing demonstrators.

The protesters tried to block the entry to the venue of the party congress, shouting slogans such as: "Keep refugees, drive Nazis away!" and "We'll get you all."

According to a police spokesperson, demonstrators blocked a road to the venue with burning tyres for half an hour. They also temporarily blocked traffic on highway A8 in both directions near Stuttgart Airport, trying to prevent AfD members who arrived by plane from attending the congress.

Hooded demonstrators lit firecrackers and threw them at police officers. The police used tear gas and a water cannon amid the clashes with the protesters. About 400 people were detained, police said.

More than 1,000 police officers were deployed on Saturday to prevent clashes between the protesters and AfD party participants.

The AfD's two-day meeting will focus on the right-wing party's policies. It is expected to adopt an anti-Islam manifesto.

The AfD has protested against German Chancellor Angela Merkel's liberal migration policy. The party has also managed to channel popular anger against the political establishment and the media.

das/jm (dpa, AFD, Reuters)