Dozens of anti-austerity protesters clashed with police yesterday after breaking into a conference centre in northern Greece to demonstrate against the presence of a German government official.

The protesting municipal workers pushed and threw coffee on Wolfgang Hölsche-Obermaier, a German consul in Thessaloniki, who was attending a conference of Greek and German mayors in the city. Hans-Joachim Fuchtel, a German Deputy Labour Minister who has been appointed special envoy to Greece, was also present.

"These people haven't come here to help us, but to announce our death sentence," said Themis Balasopoulos, leader of Greece's municipal workers union. The protesters chanted "Nazis out" as they tried to block municipal officials from the conference.

Mr Hölsche-Obermaier said he was not upset by the attack against him. "It was a misunderstanding. I am more pro-Greek than I was before today," he told reporters.

Germany contributes the most to Greece's rescue loans and has been one of the most vocal advocates of the tough austerity measures demanded of Athens. Last month, 50,000 people protested in Athens when Angela Merkel, the German Chancellor, paid her first official visit to Greece since the country's debt crisis broke out.