Anti-globalisation protesters involved in a third consecutive night of clashes with police in Hamburg are ‘crazy’, according to some refugees in the city.

Police used water cannon trucks against rioters, who hurled iron rods and pavement blocks at authorities, even after G20 leaders had left the city.

“If people did this in Egypt they would be shot,” said Ibrahim Ali, a 29-year-old Egyptian who came to Hamburg in 2011.

“The state provides everything: housing, unemployment benefits and education. Yet those people are not happy. I don't get it.”

Ali was one of three refugees serving beer, falafel and humus to protesters leaving the Sternschanze quarter, as rioters came under pressure from police special units.

"They are crazy. I can't believe my eyes," said Mohammad Halabi, 32, a Syrian who arrived in Germany as a refugee some 18 months ago.

G20 Protesters take Hamburg Show all 8 1 /8 G20 Protesters take Hamburg G20 Protesters take Hamburg German riot police use water cannons against protesters during the demonstration during the G20 summit in Hamburg, Germany REUTERS G20 Protesters take Hamburg German riot police clash with protesters during the demonstrations during the G20 summit in Hamburg, Germany REUTERS G20 Protesters take Hamburg Riot police move in through the smoke from a smoke bomb during the "Welcome to Hell" rally against the G20 summit in Hamburg, northern Germany AFP/Getty Images G20 Protesters take Hamburg Riot police use water cannon to put of burning bins as a protester runs off after the "Welcome to Hell" rally against the G20 summit in Hamburg, northern Germany AFP/Getty Images G20 Protesters take Hamburg Protesters throw beer bottles as they shield themselves from water cannon spray during the "Welcome to Hell" rally against the G20 summit in Hamburg, northern Germany AFP/Getty Images G20 Protesters take Hamburg A firefighter works at the scene where a number of cars burnt down during the G20 summit in Hamburg, Germany REUTERS G20 Protesters take Hamburg The interior of a burnt down car is seen as firefighters work in the background during the G20 summit in Hamburg, Germany REUTERS G20 Protesters take Hamburg German police remove a protestor who is blocking a street at a demonstration during the G20 summit in Hamburg, Germany REUTERS

"They have such a beautiful country and they're destroying it."

But Halabi says he cannot be angry at the German chancellor Angela Merkel, who took the decision to welcome refugees into the country.

“Without her I wouldn’t be here,” he said.

Tens of thousands of demonstrators have been protesting at the G20 international forum of world leaders.

German chancellor Angela Merkel has condemned their actions.

“I have every understanding for peaceful demonstrations but violent demonstrations put human lives in danger,” she said.

More than 200 officers have been injured, although it is not clear how many protesters were injured.

Many have been gathering in black bloc formations with dark clothing and masks, a protest tactic used by demonstrators associated with the anarchist movement.