Ankara, April 18 : Turkish security forces killed one senior figure and 13 fighters of the Kurdish militia People's Protection Units (YPG) in northern Syria, Turkey's Defence Ministry said. The YPG members were "neutralised" when they "opened harassment fire and attempted to infiltrate" into Turkey's Operation Peace Spring zone in northern Syria, the Ministry tweeted on Sunday. Turkish authorities often use the term "neutralised" to imply "terrorists" killed, wounded or captured in security operations, Xinhua news agency reported. Meanwhile, Turkish intelligence killed Mehmet Aydin, a senior figure of the YPG, in an operation in al-Darbasiyah town of the Syrian province of Hasaka. Aydin had been active in the ranks of the outlawed Kurdistan Workers' Party (PKK) within Turkish territory in previous years, before taking a role in Syria. Ankara sees the YPG as the Syrian branch of the PKK. Turkey's forces and YPG members often exchange fire on the Syrian border amid heightened tension in the region since early January after three Turkish soldiers were killed in an attack by outlawed Kurdish militants. The Turkish Army launched Operation Euphrates Shield in 2016, Operation Olive Branch in 2018, Operation Peace Spring in 2019 and Operation Spring Shield in 2020 in northern Syria. Turkish authorities say the operations aim to eliminate threats against Turkey and provide a safe zone that will facilitate the return of Syrian refugees to their homes. /IANS