ANKARA (Reuters) - An unidentified gunman attacked police in Istanbul on Saturday morning, a day after rocket attacks targeting Istanbul’s police headquarters and an office of the ruling AK Party. No casualties were reported in either attack.

The gunman in Saturday’s attack opened fire on a police vehicle in Istanbul’s Esenyurt district, then fled when police officers returned fire, the private Dogan News Agency reported. He left behind his gun and a bag of grenades, Dogan said.

Meanwhile, Turkish authorities have identified one of the assailants responsible for Friday’s attacks as a member of the outlawed Revolutionary People’s Liberation Army-Front (DHKP-C), the broadcaster NTV reported on Saturday.

There were no immediate claims of responsibility for either attack. Operations were under way to capture both suspects, Dogan and NTV reported.

A gunman who killed 39 people in an Istanbul nightclub on New Year’s Day, an attack claimed by Islamic State, is believed to be held in the police headquarters attacked on Friday. The nightclub attacker was captured in Esenyurt, where Saturday’s shooting took place.

The outlawed DHKP-C is listed as a terrorist organisation by Turkey, the United States and the European Union. It has staged suicide attacks against Turkish police and the U.S. Embassy in recent years.

NATO member Turkey has been hit by a spate of bombings and shootings in the past year, including a twin bombing claimed by Kurdish militants outside a soccer stadium in Istanbul on Dec. 10 that killed 44 people.