Shock, bewilderment: Brexit reactions pour in

For the referendum spectators, the move signals the dawn of a new era for a European Union in trouble.

The Germans were among the first to react.

Germany's vice-chancellor Sigmar Gabriel highlighted the mood with a blunt tweet for those who counted on the UK to remain an EU member state.

"Damn! A bad day for Europe," he wrote in German.

Germany's minister for the European Union, Michael Roth, was more sanguine.

"A really sad day for #UK and #Europe. Europeans must stand united now. People deserve a better #EU," he tweeted.

Frank-Walter Steinmeier, Germany's foreign minister, also described the day as sad for both Europe and the UK.

But Gerard Araud, French ambassador to Washington, was less forgiving.

"Now to the other members states to save the EU from unraveling which excludes business as usual, especially in Brussels. Reform or die!," he tweeted.

The initial reaction from the top EU leadership in Brussels was more measured and warned against the consequences to the single currency.

"You can see what is happening to sterling on the markets. I don't want the same thing to happen to the euro," said Martin Schulz, president of the EU parliament.

The value of the British pound has now slumped to its lowest level in over three decades with rating agency S&P threatening to strip the UK of its AAA credit rating.

Schulz said the EU parliament would respect the UK’s decision to leave.

"Now is the time for us to behave seriously and responsibly. David Cameron has his responsibilities for his country, we have our responsibilities for the future of the EU," he said.

But Manfred Weber, who leads the EU parliament's largest political group, the centre-right EPP, said the UK would enjoy no special treatment.

"Exit negotiations should be concluded within 2 years max. There cannot be any special treatment. Leave means leave," he noted in a tweet.

Lithuania's president Dalia Grybauskaite, for her part, summarised her view of the situation ahead in a tweet: "#Brexit: respect, regret, re-engage".

In Budapest, Hungarian PM Viktor Orban said that "the biggest lesson" from the referendum outcome was that "Brussels must hear the voice of the people".

The far-right in the Netherlands and in France, for their part, are hailing the exit as a victory.

Both Geert Wilders, leader of the Dutch Freedom Party, and Marine Le Pen, of France's National Front, want to trigger similar referendums.