German Chancellor Angela Merkel's party has suffered a historic loss in Berlin state elections, with the right-wing AfD party posting strong gains after riding a wave of anger over her open-door refugee policy.
According to projections, the anti-Islam Alternative for Deutschland (AfD) won around 14 per cent in the capital, which has long prided itself on being a diverse and multicultural city.
Support was especially strong in the vast tower-block districts in Berlin's former communist east.
The vote means the AfD has now won opposition seats in 10 of Germany's 16 states ahead of national elections next year.
Mrs Merkel's centre-right Christian Democratic Union (CDU) won just 17.5 per cent – its worst post-war result in the city.
The result likely means the end of its term as junior coalition partner to the Democrats (SPD), who won around 22 per cent.
The election in the chronically indebted city-state of 3.5 million people was dominated by local issues including poor public services, crumbling school buildings, late trains and a housing shortage, as well as problems in coping with the migrant influx.
Germany took in 1 million asylum seekers last year, and more than 70,000 of them came to Berlin.
Thousands are still housed in the cavernous hangars of the Nazi-built former Tempelhof airport, once the hub for the Cold War-era Berlin airlift.
Before the vote, Berlin's SPD Mayor Michael Mueller warned that a strong AfD result would be "seen throughout the world as a sign of the resurgence of the right and of Nazis in Germany".
The vote marked another milestone for the upstart AfD, which has campaigned on a xenophobic platform, similar to France's National Front or far-right populists in Austria and the Netherlands.
"From zero to double-digits, that's a first for Berlin," said the AfD's top Berlin candidate, Georg Pazderski.
"We've arrived in the capital," said the party's co-leader Beatrix von Storch, hailing the "huge success".
Mrs Merkel's CDU, which has a national majority, in Berlin has served as junior coalition partner to Mr Mueller's SPD, traditionally the strongest party in the city.
Mr Mueller has rejected a new coalition with the CDU and was seen likely to team up with the ecologist Greens and the far-left Die Linke party, each of whom scored around 15 per cent.