ISTANBUL - At least 31 people have been killed and 360 others injured in demonstrations during a four day “spiral of violence” led by pro-Kurdish protesters against Turkey’s policy on Syria, officials said Friday.

But Turkish President Recep Tayyip Erdogan pledged that despite the violence, the authorities would press on with efforts to make peace with Kurdish rebels who have a waged a 30-year insurgency for self-rule in eastern Turkey.

Interior Minister Efkan Ala told reporters that 31 people had been killed in the demonstrations, which left a trail of destruction and prompted the army to impose a curfew in parts of southeast Turkey.

In addition, two policemen were shot dead in the southern city of Bingol late Thursday while inspecting the scene of a demonstration, he confirmed.

Bingol province’s police chief was seriously wounded in the attack. Five “terrorists” suspected of gunning them down were themselves killed by the security forces, Ala added. “This spiral of violence should immediately be stopped,” he said in a statement in Ankara.

“Everyone should do their part to put an end to these incidents. We should all stand in solidarity with each other.” Ala said that clashes broke out in 35 cities, and 221 civilians and 139 security officials including police were wounded. 

Over 1,000 people were detained and 58 people have formally been arrested for their involvement in the protests which caused damage to 212 schools, he said. The violence, which has been concentrated in south-eastern Turkey but also flared in Istanbul and Ankara, has been among the worst rioting seen in the country in years.

The official toll has already well exceeded the number of eight people confirmed to have been killed in the May-June 2103 nationwide protests against the ruling party.

According to the official Anatolia agency, most of the deaths occurred in Diyarbakir, Turkey’s main Kurdish city, where 11 people were killed.

The fatalities were mainly concentrated in the southeast of Turkey but one person died in protests in Istanbul, it said.

The latest deaths happened late Thursday in the southeastern province of Gaziantep, where at least four people died in clashes between rival groups armed with rifles, pistols and axes, the Dogan news agency reported.

The demonstrators responded to a call late Monday by Turkey’s main pro-Kurdish party for protests against the government’s lack of action to stop the Syrian border town of Kobane falling to jihadists.

But Erdogan said the government would continue efforts to make peace with the outlawed Kurdistan Workers Party (PKK), whose supporters were heavily involved in the recent violence.

Erdogan said he would work for an agreement to make peace with the Kurds until “my last breath”, blaming the protests on “thugs and terrorists” who wanted to disrupt the process.

“I have risked my own neck in the peace process,” Erdogan said in a speech in the Black Sea city of Trabzon.

“I have put my mind and heart to it. And I will keep fighting for it until my last breath. Because I know that this nation is standing behind us,” he added in the televised speech.

The PKK has largely observed a ceasefire since March 2013 and the ruling Justice and Development Party (AKP) has kept up contacts with Kurdish politicians even amid the protests.

The PKK’s armed wing, the People’s Defence Force (HPG), said in a statement that its forces had no link to the attack on the security forces in Bingol.

The PKK’s jailed leader Abdullah Ocalan had given the government until October 15 to set out a roadmap for the peace process and there were no plans for attacks, it said.

Some of the deadly violence has also been blamed on clashes between PKK supporters and backers of the Kurdish Sunni fundamentalist group Huda-Par which is sympathetic to Islamic State jihadists.