ERBIL, Kurdistan Region – Two suspects in the Koya bombings that targeted the headquarters of a Kurdish armed party of Iranian Kurdistan, killing seven, have been arrested, Kurdish security announced Monday. The main perpetrator is still on the run.

"The security agency was able to arrest two suspects on suspicion of being involved in the crime," reads a statement from the Kurdistan Region's Asayesh released on Monday. The security agency "has been able to identify the main perpetrator who is on the run now."

The Asayesh had formed a high level committee, coordinating with security agencies of several cities including Erbil and Sulaimani to investigate the twin bombings in Koya.

Following up on solid leads, the security committee confiscated materials belonging to the main perpetrator and have intensified their efforts to arrest those responsible for the bombing that are still at large.

Last Tuesday, two bombs targeted the headquarters of the Iranian Kurdistan Democratic Party (PDK, KDP-I), known locally as HDK, killing five of its Peshmerga fighters, two members of the Kurdish security forces, and wounding three others in Koya, 70 kilometres east of Erbil.

The Kurdistan Regional Government (KRG) described the attack an act of terror.

“We reiterate that we will exhaust all the efforts to bring those responsible for this terrorist act to justice,” the KRG said in a statement last Wednesday. “We will declare to those behind this terrorist crime that every effort or plot against our nation will certainly fail.”

The HDK also described the attack as terrorism and have blamed Tehran. A senior official from the party told Rudaw they had "little doubt" about Iran's involvement in the assault.

Ismail Sharafi said investigations had started and evidence pointed to the neighboring Islamic Republic.

"We cannot at this moment identify the perpetrators of these bloody attacks, but such actions that are carried out against the PDK leave little doubt about the Islamic Republic of Iran's involvement as a terrorist regime in the region," Sharafi told Rudaw in the days after the attack.

Sharafi also added that Tehran could have funded the attack instead of being directly involved.

The twin bombings took place only minutes apart as party members were marking the birthday of their late leader Abdulrahman Ghassemloo who was assassinated in Vienna, Austria, in 1989. An Austrian court has officially accused Iranian agents of the killing which had a long-lasting impact on HDK's structures and its armed struggle for self-rule against the Islamic Republic.

Eyewitnesses told Rudaw the second blast, which appeared to have been more powerful, happened when people rushed to the site of the first attack trying to help the victims.

In the early 1990s, the HDK ended all its military campaigns against the Iranian army largely due to arrangements between Tehran and the Kurdistan Region, which prohibited attacks on Iran from the Kurdish-controlled territories in Iraq.

Tuesday’s attacks happened only months after Kurdistan Region officials directly called on Tehran to resume negotiations with the HDK.

Many pundits have speculated that the conflict between the Iranian government and the Kurds is likely to become bloodier in one of the few parts of the Middle East which has so far been spared the regional upheaval that followed the so-called Arab Spring of six years ago.