Security sources said on Sunday Serdar Tunagür, the ringleader of the PKK terrorist organization in Portugal, was apprehended during a joint operation by the Turkish National Intelligence Organization (MIT) and Istanbul police.

Tunagür, who previously engaged in subversive activities in support of the PKK, actively took part in many actions on behalf of the terrorist group in Portugal.

He was arrested in Istanbul and later sent to prison on judicial authorities’ orders. Media outlets reported that the suspect once served under the PKK in rural parts of Türkiye and in Makhmur, a PKK camp in Iraq. He has been under surveillance by intelligence for a while, sources said.

In a related development, the Turkish Ministry of Defense said on Sunday afternoon that the country's armed forces have eliminated eight members of the PKK terrorist organization's Syrian wing YPG in operation zones in Syria and Iraq.

In its 40-year terror campaign against Türkiye, the PKK, listed as a terrorist organization by Türkiye, the U.S., and the EU, has been responsible for the deaths of over 40,000 people, including women, children, infants and the elderly.

Strikes on the terrorist group have only intensified in the past two years. The PKK mounted an attack in the capital Ankara last month, as two of its members attempted to raid the headquarters of the Turkish Aerospace Industries (TAI), killing five and injuring 22 others.

Last week, as he spoke about a possible normalization with Syria's Assad regime, President Recep Tayyip Erdoğan hinted at a large-scale military offensive in that country against the PKK.

Speaking of a possible reconciliation with Syria, Erdogan said Türkiye has reached out for normalization, expressing its belief that it would open the door to peace and stability in Syrian territories.

Cross-border operations are always in the cards for the country's security, he said, expressing readiness to launch them anytime the country feels threatened as he spoke to reporters during a return flight from Saudi Arabia and Azerbaijan. Türkiye has launched several cross-border operations in recent years, in both northern Syria and northern Iraq, targeting terrorists who hide out there and destabilize the border or plot attacks on Turkish soil.

Reiterating Türkiye's commitment to fighting terrorism while respecting Syria's territorial integrity, Erdoğan said that the presence of terrorist groups in northern Syria, notably the PKK/YPG, also poses a threat to its territorial integrity, adding that the Syrian government, well aware of this, must take steps to create a new climate in the country.

Erdogan also said the "threat of Israel," right next to Syria, is no fairy tale, warning that the fire in the surrounding areas can quickly spread in the unstable lands. In northern Syria, Ankara has launched a trio of successful anti-terror operations since 2016 to prevent the formation of a terror corridor and enable the peaceful settlement of residents: Euphrates Shield (2016), Olive Branch (2018) and Peace Spring (2019).