Some 29 people were injured in a demonstration against the anti-Islam Pegida movement in the northern German city of Hanover, police said Tuesday.
Pegida opponents clashed with police in central Hanover on Monday evening leaving 24 policemen and five demonstrators injured.
Both anti-Pegida protestors and police used pepper spray. Demonstrators also threw fireworks and bottle at police.
Some 42 people were arrested, around a half of whom were from the local Pegida offshoot Hagida. They were detailed for throwing firecrackers.
While Pegida, or Patriotic Europeans Against the Islamization of the West, drew about 200 supporters onto the streets, about 2,000 people joined the anti-Pegida demonstration, according to police estimates.
Since October, Pegida has held weekly anti-Islam and anti-refugee demonstrations in the eastern city of Dresden, attracting tens of thousands of supporters.
This has sparked groups to mount similar protests in other parts of the country and for Pegida opponents to also to take to the streets.