RAS AL-AYN, SYRIA - OCTOBER 21: A photo shows a tunnel dug by PKK, listed as a terrorist organization by Turkey, the U.S. and the EU, and Syrian Kurdish YPG militia, which Turkey regards as a terror group, after Ras Al Ayn district was cleared of YPG and PKK with Turkey's Operation Peace Spring, on October 21, 2019 in Ras al-Ayn, Syria. The entrance of the tunnel, which surrounds the Syrian district of Ras al-Ayn and extending to the Turkish border from the Ras al-Ayn district center, is located inside a storage. The tunnel, which is about 13 meters below the ground, has a height of 3 meters and a width of 2.5 meters. ( Hişam el Homsi - Anadolu Agency )

RAS AL-AYN, SYRIA - OCTOBER 21: A photo shows a tunnel dug by PKK, listed as a terrorist organization by Turkey, the U.S. and the EU, and Syrian Kurdish YPG militia, which Turkey regards as a terror group, after Ras Al Ayn district was cleared of YPG and PKK with Turkey's Operation Peace Spring, on October 21, 2019 in Ras al-Ayn, Syria. The entrance of the tunnel, which surrounds the Syrian district of Ras al-Ayn and extending to the Turkish border from the Ras al-Ayn district center, is located inside a storage. The tunnel, which is about 13 meters below the ground, has a height of 3 meters and a width of 2.5 meters. ( Hişam el Homsi - Anadolu Agency )

RAS AL-AYN, SYRIA - OCTOBER 21: A photo shows a tunnel dug by PKK, listed as a terrorist organization by Turkey, the U.S. and the EU, and Syrian Kurdish YPG militia, which Turkey regards as a terror group, after Ras Al Ayn district was cleared of YPG and PKK with Turkey's Operation Peace Spring, on October 21, 2019 in Ras al-Ayn, Syria. The entrance of the tunnel, which surrounds the Syrian district of Ras al-Ayn and extending to the Turkish border from the Ras al-Ayn district center, is located inside a storage. The tunnel, which is about 13 meters below the ground, has a height of 3 meters and a width of 2.5 meters. ( Hişam el Homsi - Anadolu Agency )

RAS AL-AYN, SYRIA - OCTOBER 21: A photo shows a tunnel dug by PKK, listed as a terrorist organization by Turkey, the U.S. and the EU, and Syrian Kurdish YPG militia, which Turkey regards as a terror group, after Ras Al Ayn district was cleared of YPG and PKK with Turkey's Operation Peace Spring, on October 21, 2019 in Ras al-Ayn, Syria. The entrance of the tunnel, which surrounds the Syrian district of Ras al-Ayn and extending to the Turkish border from the Ras al-Ayn district center, is located inside a storage. The tunnel, which is about 13 meters below the ground, has a height of 3 meters and a width of 2.5 meters. ( Hişam el Homsi - Anadolu Agency )

RAS AL-AYN, SYRIA - OCTOBER 21: A photo shows a tunnel dug by PKK, listed as a terrorist organization by Turkey, the U.S. and the EU, and Syrian Kurdish YPG militia, which Turkey regards as a terror group, after Ras Al Ayn district was cleared of YPG and PKK with Turkey's Operation Peace Spring, on October 21, 2019 in Ras al-Ayn, Syria. The entrance of the tunnel, which surrounds the Syrian district of Ras al-Ayn and extending to the Turkish border from the Ras al-Ayn district center, is located inside a storage. The tunnel, which is about 13 meters below the ground, has a height of 3 meters and a width of 2.5 meters. ( Hişam el Homsi - Anadolu Agency )

RAS AL-AYN, SYRIA - OCTOBER 21: A photo shows the entrance of a tunnel dug by PKK, listed as a terrorist organization by Turkey, the U.S. and the EU, and Syrian Kurdish YPG militia, which Turkey regards as a terror group, after Ras Al Ayn district was cleared of YPG and PKK with Turkey's Operation Peace Spring, on October 21, 2019 in Ras al-Ayn, Syria. The entrance of the tunnel, which surrounds the Syrian district of Ras al-Ayn and extending to the Turkish border from the Ras al-Ayn district center, is located inside a storage. The tunnel, which is about 13 meters below the ground, has a height of 3 meters and a width of 2.5 meters. ( Hişam el Homsi - Anadolu Agency )

RAS AL-AYN, SYRIA - OCTOBER 21: A photo shows the entrance of a tunnel dug by PKK, listed as a terrorist organization by Turkey, the U.S. and the EU, and Syrian Kurdish YPG militia, which Turkey regards as a terror group, after Ras Al Ayn district was cleared of YPG and PKK with Turkey's Operation Peace Spring, on October 21, 2019 in Ras al-Ayn, Syria. The entrance of the tunnel, which surrounds the Syrian district of Ras al-Ayn and extending to the Turkish border from the Ras al-Ayn district center, is located inside a storage. The tunnel, which is about 13 meters below the ground, has a height of 3 meters and a width of 2.5 meters. ( Hişam el Homsi - Anadolu Agency )

RAS AL-AYN, SYRIA - OCTOBER 21: A photo shows the entrance of a tunnel dug by PKK, listed as a terrorist organization by Turkey, the U.S. and the EU, and Syrian Kurdish YPG militia, which Turkey regards as a terror group, after Ras Al Ayn district was cleared of YPG and PKK with Turkey's Operation Peace Spring, on October 21, 2019 in Ras al-Ayn, Syria. The entrance of the tunnel, which surrounds the Syrian district of Ras al-Ayn and extending to the Turkish border from the Ras al-Ayn district center, is located inside a storage. The tunnel, which is about 13 meters below the ground, has a height of 3 meters and a width of 2.5 meters. ( Hişam el Homsi - Anadolu Agency )

RAS AL-AYN, SYRIA - OCTOBER 21: A photo shows the entrance of a tunnel dug by PKK, listed as a terrorist organization by Turkey, the U.S. and the EU, and Syrian Kurdish YPG militia, which Turkey regards as a terror group, after Ras Al Ayn district was cleared of YPG and PKK with Turkey's Operation Peace Spring, on October 21, 2019 in Ras al-Ayn, Syria. The entrance of the tunnel, which surrounds the Syrian district of Ras al-Ayn and extending to the Turkish border from the Ras al-Ayn district center, is located inside a storage. The tunnel, which is about 13 meters below the ground, has a height of 3 meters and a width of 2.5 meters. ( Hişam el Homsi - Anadolu Agency )

RAS AL-AYN, SYRIA - OCTOBER 21: A photo shows the entrance of a tunnel dug by PKK, listed as a terrorist organization by Turkey, the U.S. and the EU, and Syrian Kurdish YPG militia, which Turkey regards as a terror group, after Ras Al Ayn district was cleared of YPG and PKK with Turkey's Operation Peace Spring, on October 21, 2019 in Ras al-Ayn, Syria. The entrance of the tunnel, which surrounds the Syrian district of Ras al-Ayn and extending to the Turkish border from the Ras al-Ayn district center, is located inside a storage. The tunnel, which is about 13 meters below the ground, has a height of 3 meters and a width of 2.5 meters. ( Hişam el Homsi - Anadolu Agency )

RAS AL-AYN, SYRIA - OCTOBER 21: A photo shows the entrance of a tunnel dug by PKK, listed as a terrorist organization by Turkey, the U.S. and the EU, and Syrian Kurdish YPG militia, which Turkey regards as a terror group, after Ras Al Ayn district was cleared of YPG and PKK with Turkey's Operation Peace Spring, on October 21, 2019 in Ras al-Ayn, Syria. The entrance of the tunnel, which surrounds the Syrian district of Ras al-Ayn and extending to the Turkish border from the Ras al-Ayn district center, is located inside a storage. The tunnel, which is about 13 meters below the ground, has a height of 3 meters and a width of 2.5 meters. ( Hişam el Homsi - Anadolu Agency )