Update 2 | Istanbul prosecutor wounded, two hostage takers killed

Turkish security forces cut short a standoff with a far-left group that captured prosecutor Mehmet Selim Kiraz, when they launched a storm on an Istanbul court. All hostage takers are dead, and the court official wounded, confirmed police officials.

"We negotiated with the terrorists for six hours, but began the storm when we heard gunshots from the prosecutor's office," said Istanbul's security chief, Selami Altınok. "He has been delivered to hospital in serious condition, and is being operated on. The two terrorists are dead."

The Turkish prosecutor was probing the politically sensitive death of an anti-government protester was taken hostage by an armed group at an Istanbul courthouse, Turkish media reported.

Prosecutor in case into killing of #Gezi's victim taken hostage in #Istanbul courthouse http://t.co/ykRW6mXCDD pic.twitter.com/hXufv5js9s

— Hurriyet Daily News (@HDNER) March 31, 2015

Turkish prosecutor taken hostage at #Istanbul courthouse http://t.co/TOlMduuVin via @HDNER #Turkey pic.twitter.com/eKVYrRZh5C

— FRANCE 24 (@FRANCE24) March 31, 2015

Mehmet Selim Kiraz was investigating the killing of 15-year-old Berkin Elvan, who died in March last year after spending 269 days in a coma due to injuries inflicted by police in the mass protests of early summer 2013.

Gunfire was heard at the courthouse, the Dogan news agency reported.

Armed men belonging to the leftist group Revolutionary People's Liberation Party-Front (DHKP/C) reportedly threatened to kill Kiraz if the officer who shot Berkin was not arrested.

The group set a deadline for 15:35 local time for their demands to be met, local media reported.

Turkish news channel NTV showed photos on its website of a an armed man holding a gun to the prosecutors head while his hands were tied. 

Special forces were dispatched to the courthouse to counter the hostage situation.