Updated as of 4:40 p.m. EDT: Prosecutor Mehmet Selim Kiraz was “dead when he arrived” at Florence Nightingale hospital in Istanbul after being shot five times by far-left radical militants after they stormed his courthouse office Tuesday and took him hostage.

The two gunmen, who said they were part of the Revolutionary People’s Liberation Party Front, or DHKP/C, were killed by police who stormed the office after hearing gunshots inside. Kiraz was shot three times in the head and twice in the body, according to Sputnik News. The gunmen demanded that the police officer who struck and killed 15-year-old Berkin Elvan during a protest in 2013 be arrested or they would kill Kiraz.

Updated as of 2:38 p.m. EDT: Police in Istanbul said two gunmen were shot dead Tuesday night and the prosecutor they took hostage in a city courthouse earlier in the day was seriously injured in a shootout, according to a tweet from Rueters. Gunshots were heard from inside around 9 p.m. local time, prompting law enforcement to initiate rescue efforts, the Daily Sabah reported.  

Original story: A group of gunmen Tuesday stormed a courthouse in the Turkish capital city of Istanbul and took a prosecutor as its hostage, according to multiple reports. The gunmen are allegedly part of a banned leftist group, and they have laid out a list of demands and threatened to kill the prosecutor if their demands aren't met.

The hostage has been identified by Turkish news outlet Anadolu Agency and state television as chief prosecutor Mehmet Selim Kiraz, according to the Associated Press. Kiraz is currently leading the investigation into the death of Berkin Elvan, a teenage boy who was killed in 2013 after a police cannister of gas was fired and fatally hit him during anti-government demonstrations. The group responsible for holding him hostage was named as DHKP/C by RT.

The Daily Sabah reported several gunshots being heard from the Çağlayan courthouse, but an Istanbul-based journalist who posted a Twitter photo from inside downplayed those reports.

The group's demands include a confession on live television by police to the killing of Berkin and charges dropped against protesters who took part in the demonstration so that the police may be tried in the "people's court." The Daily Sabah reported that Berkin's father has said "blood cannot be washed away with blood." DHKP/C has given a deadline of 3:36 p.m., local time.

A reporter for Hürriyet placed a phone call to Kiraz's cell phone that was answered by an unidentified person who said, "The prosecutor is not available right now."

Law enforcement officials, including special operations teams, have convened on the scene and were reportedly outside of the courthouse cordoning off a boundary around the building that was being evacuated.

The hostage incident comes as the entire country was struck by a massive blackout earlier in the day, rendering a number of public services in Istanbul useless, including public transportation and airport services. Prime Minister Ahmet Davutoğlu did not rule out a terror attack being responsible for the power outage.