Several days of unrest in Sweden, sparked by a far-right group’s burning of the Koran, have injured at least 40 people, police said on Monday, calling for more resources to deal with the violence.

More Muslim countries meanwhile protested the burning of their religion’s holy book.

Protests have turned violent in several cities since Thursday, leaving 26 police officers and 14 civilians injured, police said at a press conference on Monday. About 20 police vehicles were burned or damaged.

Officials in several Muslim countries condemned the move that sparked the protests: the burning of the holy book by the leader of the anti-immigration and anti-Islam group Hard Line, the Danish-Swedish politician Rasmus Paludan.

Aiming to drum up support ahead of September elections, he has declared a “tour” of Sweden, planning to visit cities and towns with large Muslim populations with the intent of burning copies of the Koran as the faithful mark the holy month of Ramadan.

Paludan intends to stand in the September poll but does not yet have the necessary signatures to secure his candidacy.

Clashes with police have erupted during protests against the group since Thursday evening, starting in the cities Linkoping and Norrkoping.

They spread to the city of Malmo, where Paludan burned a Koran on Saturday. A school was set alight during a second night of unrest Saturday-Sunday.

‘Too few of us’

Police said they believed the violence was targeted at their officers.

National police chief Anders Thornberg said rioters had “tried to kill police officers.

“Criminals have profited from the situation to show violence toward society, without any link to the demonstrations,” he told journalists Monday.

“There are too few of us. We have grown, but we have not grown at the same pace as the problems at the heart of society,” he added, calling for more resources for the police.

As protesters burned cars and lobbed rocks at the police in Sunday’s clashes, officers responded, head of police special forces Jonas Hysing said.

“Some 200 participants were violent and the police had to respond with arms in legitimate self-defence,” he said.

Police had earlier said officers had wounded three people after firing warning shots during Sunday’s “riot” in the city of Norrkoping. Eight people were arrested there and 18 in the neighbouring city of Linkoping.

Police special operations commander Jonas Hysing told the press conference that officers had acted in self-defence.

Iraq’s foreign ministry said on Sunday it had summoned the Swedish charge d’affaires in Baghdad.

It warned the affair could have “serious repercussions” on “relations between Sweden and Muslims in general, both Muslim and Arab countries and Muslim communities in Europe”.

Saudi Arabia’s official news agency said the kingdom has “condemned the agitations of certain extremists in Sweden and their provocations against Muslims”.

And the Turkish foreign ministry denounced “hesitation to prevent provocative and Islamophobic acts… under the cover of freedom of expression”.

A demonstration was held outside the Swedish embassy in Tehran.