At least 20 people were feared dead Saturday in twin explosions in Turkey’s capital Ankara, targeting activists gathering for a peace rally organised by leftist and pro-Kurdish groups.

Eyewitnesses told AFP several corpses were seen lying on the ground while NTV television and the Dogan news agency said at least 20 people were killed. Some 100 people were wounded, NTV added.

Initial reports said one huge explosion had gone off but Turkish media said later there had been two separate blasts in short sequence.

The authorities were exploring the possibility that the blasts could have been caused by a suicide bomber, the official Anatolia news agency said.

Prime Minister Ahmet Davutoglu had been briefed over the blast by Health Minister Mehmet Muezzinoglu, it added.

“We are investigating the explosion and will share our findings with the public as soon as possible,” Turkish official told AFP, without giving further details.

The area was to have hosted a peace rally organised by leftist groups later in the day, including the pro-Kurdish Peoples’ Democratic Party (HDP).

The attack comes with Turkey on edge ahead of November 1 polls and a wave of unrest over the last months.

Fighting has resumed between the militant Kurdistan Workers’ Party (PKK) and government forces after the collapse of a two-year ceasefire in July.

Over 140 members of the security forces have since been killed while Ankara claims to have killed over 1,700 Kurdish militants in a relentless bombing campaign.