Clashes between protesters and police have brought a halt to proceedings in the Ukrainian parliament as nationalists demonstrated outside, demanding recognition for a controversial World War II partisan group.

Under Stepan Bandera, the Ukrainian Insurgent Army (UPA) – the military branch of the Organisation of Ukrainian Nationalists – fought Soviets, Poles and Germans for an independent Ukraine.

But the nationalists were temporarily allied with the Nazis in their struggle against the Soviet Union, are still viewed in some quarters as collaborators, and allegedly committed atrocities against Polish civilians.

Amid increasing tension outside parliament, smoke cannisters and stones were thrown at police and windows were blown out by air guns.

The far-right Svoboda party which organised the demonstration said its members were not responsible for the unrest. The nationalist group Right Sector also denied involvement.

Several attempts to gain formal recognition for the UPA have failed.

As tensions mount ahead of elections later this month, Ukraine’s interior ministry described the violence as provocation aimed at destabilising the situation in the country.