Police in Heidenau were faced with three consecutive nights of violent protests  which eventually inflicted injuries on dozens of police officers.

 German Chancellor Angela Merkel has strongly condemned violence at the asylum seekers' shelter. The clash began on Friday night and prompted the reinforcement of security at the newly-opened centre in Heidenau near Dresden at the weekend after two nights of protests.

Left-wing activists staging counter-demonstrations have clashed with the right-wing protesters.

Germany says it expects up to 800,000 to seek asylum by the end of 2015.

Mrs Merkel's spokesman said it was "abhorrent how right-wing extremists and neo-Nazis attempt to spread their idiotic message of hatred around an asylum shelter".

German news magazine Der Spiegel reports that the violence on Friday night followed a demonstration earlier in the evening, called for by a Facebook group linked to the far-right NPD party.

The group later distanced itself from the violence that followed.

Police had to use tear gas and pepper spray in the early hours of Saturday morning to lift a blockade of the asylum seekers' shelter. Hundreds of people, some alcohol-fuelled, hurled bottles and stones at police, injuring 31 officers, reports say.

A further night of violence followed on Saturday, and two police officers were injured.

German media report that a police "control zone" introduced in the area immediately around the centre on Sunday appears to be working. The violence between left and right-wing groups on Sunday night took place outside this zone.

Vice Chancellor Sigmar Gabriel, visiting Heidenau on Monday, praised the town's mayor for his courage in speaking out against the violence.

Mr Gabriel was also due to speak to the refugees on Monday and tour the building where they are being lodged, which is in a former DIY store.

About 300 asylum seekers have already arrived at the reception centre, which is due to take 600 people.

Germany's Interior Minister Thomas de Maiziere has promised to use "the full force of the law" against those who carry out anti-refugee violence.

Sigmar Gabriel (right) talked to residents as well as visiting the asylu