Turkey's state-run news agency says authorities have arrested an Islamic State militant suspected of involvement in the twin suicide bombings at a peace rally in the capital Ankara in October that killed 103 people.

Anadolu Agency said the man was detained in the city of Gaziantep, near the border with Syria, on Wednesday. A court in Ankara charged him with membership in a terror organization and ordered him arrested on Thursday.

The man is the fifth suspect detained in the ongoing investigation into the attack, the deadliest in Turkey in recent years.

Anadolu said the suspect is accused of obtaining and carrying the explosives used in the attack — a charge he rejected during questioning.

Two other Islamic State suicide bombings in Istanbul this year killed 16 people.