A pro-Kurdish political party has condemned the attack on a Kurdish wedding party in southeastern Turkey that killed at least 50 people and wounded dozens of others.

The People's Democratic Party, or HDP, blamed Islamic State group for the attack in Gaziantep after Turkish President Recep Tayyip Erdogan also said the extremist group was behind the bombing.

The HDP said "we condemn and curse the ones who launched this attack, both the forces and ideology behind their actions."

The party also suggested that IS group carried out the attack hours after another Kurdish political party announced plans to negotiate to try to end a three-decade conflict between Kurdish militants and the Turkish government.