By Emre Peker

ISTANBUL—A Kurdish politician in Turkey was repeatedly stabbed on Tuesday, escalating tensions between the government and the country’s Kurds as peace talks to end a three-decade insurgency reach a critical phase.

Ahmet Karakas, an executive committee member at the pro-Kurdish People’s Democratic Party, or HDP, was stabbed seven times on his neck, leg and stomach area, spokeswoman Meral Danis said in a phone interview.

An assailant struck Mr. Karakas as he entered the HDP headquarters in the capital Ankara, at about 9:30 a.m. The politician was rushed to hospital and doctors said his condition is improving, despite ongoing bleeding in his liver and spleen, Ms. Danis said.

Police have apprehended a suspect, who is under interrogation and hasn’t yet been named.

The attempted killing of a Kurdish politician marks an escalation of the domestic crisis that has gripped Turkey since early October, when Kurdish protests over government policies toward Syria ended with clashes killing more than 40 people.

The government and the HDP have been locked in a month-long war of words, blaming each other for the violence and posing fresh challenges to President Recep Tayyip Erdogan ’s two-year-old push to establish lasting peace with the country’s Kurds.

“This attack is a result of the lynching campaign against our party that has been going on for days,” the HDP said in a statement, blaming the government and some media organizations.

After getting briefed by Interior Minister Efkan Ala on the attack, Prime Minister Ahmet Davutoglu denied the allegations from Kurdish politicians.

“I condemn this act of violence. There can be no excuse for such an attack on any politician, or citizen,” Mr. Davutoglu said. He also called on the HDP

Just before his remarks on the assault, Mr. Davutoglu was addressing lawmakers from his governing party in parliament, where he accused Kurdish politicians of responding to the Cabinet’s proposal to advance peace talks by “taking their thuggery to a peak” with the deadly Oct. 6-7 protests.

Turkey’s Kurds have been demonstrating against the government’s refusal to provide military aid to their besieged kin in Syria’s Kobani region, where Kurdish militias have been fighting since mid-September against Islamic State, also known as ISIS or ISIL.

The conflict has been rattling Turkey’s political landscape, with the government accusing Kurds of fomenting unrest to derail its delicate peace process, and Turkish Kurds charging that officials are plotting against their people at home and abroad.

Turkey has absorbed some 200,000 Kurdish refugees from Kobani as they fled the Islamic State militias, and provides humanitarian aid. But the Ankara government has been reluctant to allow passage of weapons, ammunitions and fighters to the besieged city, saying that would strengthen Syrian Kurdish militias affiliated with the Kurdistan Workers’ Party, or PKK.

Meanwhile, Ankara allowed hundreds of Iraqi Kurdish forces and Western-backed Free Syrian Army fighters to cross into Kobani to aid Syrian Kurds in an effort to clear the city of Islamic State militants. Simultaneously, Mr. Erdogan has sharply criticized its North Atlantic Treaty Orgaization ally, the U.S., for facilitating weapons airdrops that the Turkish president says is arming terrorists.

Turkey’s Kurds comprise about 18% of the 77 million population. The PKK, which has been listed as a terrorist organization by Washington and Ankara, has been fighting for autonomy in southeastern Turkey at a cost of more than 40,000 lives since 1984. A shaky cease-fire declared March 2013 by its jailed leader, Abdullah Ocalan, has largely held, but the past month saw Turkish strikes on PKK camps as the militants attacked military outposts.

The Wall Street Journal