Hamburg police and witnesses told news agencies that the clashes that broke out at two separate demonstrations on Friday's May 1 holiday resulted in numerous injuries, including to some police officers. Precise figures were not immediately available.

Police said two separate demonstrations took place in the St. Pauli and Altona districts.

The St. Pauli demonstration, in which an estimated 700 left-wing protesters had gathered, was quickly brought to a halt by police shortly after it started, as some of the participants had covered their faces and pelted the officers with rocks, bottles and firecrackers.

Police used water cannon to break up the rally of between 1,000 and 1,500 people in Altona after some of the demonstrators threw firecrackers at them. Scuffles between police and small groups of protesters continued for some time after the main demonstrations had been dispersed, but by late Friday evening the situation had calmed down.

Berlin rallies

In Berlin, on the other hand, police reported that the May 1 holiday had been relatively quiet, with only a few incidents around the protest march, in which they estimated that 18,000 people had taken part.

Police said some officers, police vehicles and police buildings had been hit by rocks, bottles or bags of paint. The main issues the demonstrators were protesting against this year were rising costs of rental accommodation and the government's policy on refugees.

In the past, there has been serious violence at May 1 demonstrations in the German capital, but in the past couple of years they have tended to be calmer.

Elsewhere in Germany, there was alarm in the eastern city of Weimar after a group of 40 to 50 right-wing extremists tried to break up a May 1 demonstration.

Meanwhile, in Turkey, police in Istanbul used water cannon and tear gas to break up a May 1 rally.

pfd/bk (dpa, AFP)