FNA- Undersecretary of Iran's Supreme National Security Council (SNSC) Reza Seifollahi confirmed that the terrorists who attacked the parliament building and the holy shrine of late Imam Khomeini in Tehran on Wednesday were Iranian nationals tempted by the ISIL terrorist group.

"These were people who had joined the ISIL from certain regions in Iran," Seifollahi said in an interview with the state-run TV on Wednesday night.

Stressing Iran's serious campaign against terrorism, specially the ISIL, inside the country and Iraq and Syria and the terrorist group's wrath from Tehran's effective anti-terrorism measures, he said, "The Iranian security forces have foiled 58 plots to carry out such terrorist operations so far."

Four unknown male assailants attacked the parliament building in Iranian capital, killing and scores of people in the hallway on Wednesday morning. Also, another group of terrorists�raided the holy shrine of the late founder of the Islamic Republic, Imam Khomeini, South of the Tehran on Wednesday morning, killing and wounding tens of people in a bomb attack and a shooting spree.

The Iranian security and Islamic Revolution Guards Corps (IRGC) forces killed all the four terrorists who attacked the parliament building on Wednesday morning, bringing the situation under control after several hours of clashes on evening.

Meantime, caretaker of Iran's emergency unit announced that the number of martyred people in the two terrorist attacks on the parliament and the holy shrine of the late founder of the Islamic Republic, Imam Khomeini, in Tehran has increased to 13, adding that 43 people were wounded.

The ISIL terrorist group claimed responsibility for the Wednesday morning terrorist attacks at the Iranian parliament and the holy shrine of late Imam Khomeini in Tehran.

Amaq news website affiliated to the ISIL reported that the Takfiri terrorist group has claimed the responsibility for the terrorist attacks in Tehran.

Iran's President Hassan Rouhani in a message on Wednesday said the twin attacks in Tehran were committed by the terrorists who have been hired by his country's enemies to strike at Tehran for their frequent losses in the region, ensuring that his nation would enhance the war on terrorism more resolutely.

Also, Iran's Islamic Revolution Guards Corps (IRGC) in a statement issued on Wednesday afternoon vowed to take revenge for the twin terrorist attacks.

"The public opinion in the world, specially the Iranian nation sees this terrorist action that happened a week after the joint meeting of the US president with the heads of one of the reactionary regional states that has constantly been supporting Takfiri terrorists as to be very meaningful, and believes that ISIL's acknowledging the responsibility indicates their complicity in this wild move," the IRGC statement said.

The powerful military force further warned that it would not miss a single moment to avenge the incident, saying, "The IRGC has proved that it would not leave unanswered the shedding of innocent blood and it ensures the Iranian nation that it will not hesitate even for a moment to protect the country's national security and the lives of the dear people, as it killed all these terrorists with the help of the Law Enforcement Force today."

Meantime, Iran's Supreme Leader Ayatollah Seyed Ali Khamenei described the twin terrorist attacks in Tehran as insignificant moves, saying that such incidents prove the country's strategy of resistance and war on terrorism was well-thought and insightful.

"The Iranian nation is moving ahead and the fumbling with firecrackers performed today will leave no impact on people's willpower," Ayatollah Khamenei said at a meeting with a group of students and representatives from the university student associations from across the nation here in Tehran on Wednesday evening.

"Everyone should know that they are too little to be able to influence the willpower of the Iranian nation and the country's officials. And these incidents, of course, revealed if the Islamic Republic had not displayed resistance at the heart of all this conspiracy, we would�ve had much more trouble of this sort in the country. God willing, they will bite the dust," he added.