Twin blasts at a pro-Kurdish peace rally in the Turkish capital Saturday killed at least 86 people and wounded nearly 200 others in the deadliest attack in Turkey’s recent history.

The explosions occurred near the main exit of the railway station in the Ulus district of Ankara, presumably intended to cause a high death toll among participants at the rally, which was organized by labor and civil society groups.

There was chaos and confusion at the scene of the bombings, with emergency workers, survivors and police trying to restore order. Bodies lay on the ground, and the yellow flags of the pro-Kurdish People’s Democratic Party (HDP) and clothes were scattered around.

Analysts suspect either the Islamic State militant group or Turkish nationalists opposed to the outlawed Kurdistan Workers’ Party (PKK) were behind the attack. No group has claimed responsibility.

‘Heinous attack’

Turkey’s president, Recep Tayyip Erdoğan, condemned the blasts as a “heinous attack on our unity and our country’s peace.”  He canceled his next three days of appointments to focus on the security challenge to Turkey.

Turkish Prime Minister Ahmet Davutoglu said the country should unite and act against terrorism, and he called for three days of national mourning. He said there were indications that two suicide bombers had carried out the blasts.