The bombings that killed at least 95 peace activists in Ankara, Turkey, have inflamed political tensions ahead of crucial snap elections less than three weeks away. As opposition Kurdish groups seek to splinter the ruling AK Party’s majority rule, the government has suggested separatist Kurds may have been behind the deadly terror attacks.

Prime Minister Ahmet Davutoğlu said Saturday two suicide bombers carried out the attack, which struck a 14,000-strong demonstration in front of the Ankara train station. He announced a three-day mourning period for victims of the attack, which left some 246 people injured, the government said.

RTS3TZR People carry an injured man after an explosion during a peace march in Ankara, Turkey, Oct. 10, 2015. Photo: Tumay Berkin/Reuters

Calling for Turkish people to “stand shoulder to shoulder against terrorism,” Davutoğlu suggested the attack may have originated from one of four groups described by the government as terrorist organizations, including the Islamic State group and the Kurdistan Workers Party (PKK), which the U.S. and Turkey both consider a terrorist group.

The PKK in northern Iraq has faced attacks in recent months from both the Islamic State, also known as ISIS, and the Turkish government, which carried out a weekslong bombing campaign against PKK positions as the Kurdish fighters struggled to repel ISIS advances. The PKK has carried out its own attacks against Turkish soldiers in recent months.

The pro-Kurdish HDP party, which has previously brokered talks between the government and the PKK, blamed state leaders for the attacks. HDP head Selahettin Demirtas canceled all election rallies, calling government officials “murderers” in the wake of the attacks, the BBC reported.

Activists have criticized the government for cracking down on free speech in recent months. Turkish intellectuals took to Twitter in the hours after the attacks to excoriate the government for failing to stop the attacks. Protesters, who scuffled with security forces moments after the dual explosions, accused police of blocking ambulances and rescuers.

Turkey explosions An injured man hugs an injured woman after explosions during a peace rally in Turkey's capital, Ankara, Oct. 10, 2015. Photo: Tumay Berkin/Reuters

President Barack Obama called Turkish President Recep Tayyip Erdoğan Saturday to extend condolences for the civilian losses. Secretary of State John Kerry also reached out to reiterate U.S. support for Turkey’s counterterror operations.

The rally was called by a cross-section of Turkish civil society groups, including trade unions and activists from the HDP. Demonstrators were seen carrying signs reading “peace” and singing together in a video taken moments before the twin blasts.