Five people were injured in the incident, during which a group of neo-Nazis attacked two buses full of left-wing activists at a motorway rest stop after more than 10,000 people protested a massive far-right demonstration in Dresden.
“The neo-Nazis attacked our two buses with the words ‘attack anti-fascists,’ bottles and blocks of ice weighing several kilos,” Holger Kindler, head of the Confederation of German Trade Unions (DGB), which took part in the anti-fascist protest, told news agency AP.
One man suffered a severe skull fracture when between 15 and 20 neo-Nazis attacked the occupants of two buses at Teufelstal near Jena on the A4 motorway when they were returning to their vehicles after a pit stop. He was to undergo surgery on Monday, news agency DDP reported.
The attack on the some 80 union members, peace activists and Left party members occurred when the group was on its way home from protesting a 6,000 strong neo-Nazi march to commemorate the victims of the 1945 Allied bombing raids on the eastern German city.
The bus full of 41 neo-Nazis had left the scene of the attack by the time police arrived, but they were stopped some 15 kilometres down the road, where police took down their personal information, authorities said.
In addition to the Swedes, police believe the rest stop attackers also came from the German states of Hesse, Rhineland-Palatinate and Saarland.
At the time, police elected not to arrest anyone on the bus.
But upon learning of the severity of the injuries sustained by the victims of the attack, police on Monday issued a nationwide warrant for three Swedish neo-Nazis who were on the bus.
Though authorities aren't sure whether they were among those who participated in the violence, they are still considered a flight risk, news agency DPA reported.
“It is inconceivable that the departure of these dangerous thugs could go unobserved by the police,” Deputy Chairman of the Left party Bodo Ramelow told DPA, demanding an investigation by the Thuringia state parliament.
But a spokesperson from the Thuringia Interior Ministry said it would have been impossible for authorities to enact a “total surveillance” on all demonstration participants.
More than 4,000 police from several states were on hand in the eastern German city on Sunday to prevent conflict between the two groups over their differing views on the air raid anniversary.