Counterterrorism teams enforced strict security measures around the Kozlu Cemetery in İstanbul's Zeytinburnu district, and 10. Yıl Street, which runs in front of the cemetery, has been closed to traffic.
The search was reportedly based on the testimony of 19 suspects detained during anti-PKK operations in İstanbul and Diyarbakır. The explosives unearthed were taken to the İstanbul Police Department for examination.
Responding to questions from reporters in front of the İstanbul Police Department, İstanbul Police Chief Hüseyin Çapkın said the explosives found seem to be of two different types. He said a hand grenade was also discovered during the search.
Çapkın said the explosives found in the graveyard are equal to 500 kilograms of hand grenades. He added that 15 people were detained in relation to the operation.
Speaking to reporters about the operation, İstanbul Governor Hüseyin Avni Mutlu said 11 kilograms of the explosives were A4 explosives.
In March of this year, İstanbul counterterrorism teams carried out excavations at two sites in İstanbul in search of explosives as part of a terrorism investigation and found 15 kilograms of plastic explosives at one of the sites. The searches were carried out as part of an investigation into the Kurdistan Communities Union (KCK), a political umbrella organization that includes the PKK.
Also in January, police discovered nearly five kilograms of explosives in the Başakşehir district of İstanbul after a dig at a site near the Atatürk Olympic Stadium that was carried out as part of the KCK investigation.
Meanwhile in another operation against the KCK, police detained four people in Van's Başkale district on Tuesday. The suspects are accused of membership in a terrorist organization and aiding and abetting a terrorist organization. In a written statement released on Tuesday, the Van Police Department said the detainees were working as couriers between PKK camps and were involved in smuggling to provide money for the organization.
Police later searched addresses of the suspects and seized cell phones, SIM cards, laptops and documents. The suspects will be taken to the Van Specially Authorized Deputy Chief Public Prosecutor's Office after being interrogated by the police.
The investigation into the KCK, which prosecutors say is a group that controls the PKK and other affiliated groups, started in December 2009, and a large number of suspected KCK members, including several mayors from the Peace and Democracy Party (BDP), have been detained. The suspects are accused of various crimes, including membership in a terrorist organization, aiding and abetting a terrorist organization and attempting to destroy the country's unity and integrity. BDP officials say the investigation is the government's way of suppressing BDP politicians, denying any links between the BDP suspects and terrorist organizations.