Turkish police arrested a total of 17 people in connection with a terrorist bombing last week in Istanbul, the state-run news agency Anadolu reported on Friday.

Authorities have blamed the deadly attack on Kurdish militant groups, although the groups have denied involvement.

What do we know about the arrests?

According to Anadolu, the 17 people ordered to pre-trial detention include the main suspect behind the bombing.

The court also released three other suspects from custody pending trial.

An additional 29 people who were rounded up in the wake of the attack have been slated for deportation. The report did not provide further details on the people who face expulsion from Turkey.

The public prosecutor's office has accused the suspects of "violating state unity," premeditated murder, as well as other charges. A trial date will be set after prosecutors prepare their indictment, which means the suspects will likely remain in pre-trial detention for months.

What happened in the bombing?

On November 13, an explosion targeted Istanbul's lively Istiklal Avenue, which is lined with restaurants and shops.

Six people were killed when a TNT-laden bomb detonated. Two children were among those killed, while over 80 people were wounded.

Investigators interrogated the woman believed to be the main suspect behind the attack for five hours, Anadolu reported.

The 23-year-old Syrian national allegedly admitted to leaving an explosives-laden bag on a bench in the street, but said she did not know what was inside of it.

She reportedly told investigators that she was acting on the instructions of a man who told her to leave the bag on the bench. After she got up and left, the bag exploded.

Turkish authorities have blamed the attack on the outlawed Kurdistan Workers' Party (PKK) as well as Syrian Kurdish militia YPG. The PKK denied any involvement.

The November 13 attack was the deadliest to hit Turkey in five years. It also brought up memories of a series of nationwide bombings from 2015 to 2017 that Turkish authorities blamed on Kurdish militants and members of the so-called Islamic State (IS) militant group.