A group of Turkish troops have been deployed to a military base in Qatar amid the diplomatic crisis between Doha and a Saudi-led quartet of Arab countries.

The Turkish troops arrived at Al Udeid Air Base in southern Doha on Tuesday, Turkey’s Daily Sabah cited Qatar’s Defense Ministry as saying.

The soldiers will join another group of Turkish troops, which were previously stationed in the Tariq bin Ziyad military base in Qatar.

The deployment is part of a 2014 defense deal between Turkey and Qatar for establishment of a Turkish military base in the Persian Gulf kingdom.

The first group of Turkish troops arrived in Qatar in June and staged their first drill at Tariq bin Ziyad military base.

Turkey has sided with Qatar since Saudi Arabia, the UAE, Bahrain and Egypt severed diplomatic ties with Doha on June 5, accusing the kingdom of sponsoring terrorism and destabilizing the region.

The four countries have also imposed a series of economic sanctions against Doha while barring Qatari aircraft from using their airspace. Qatar’s only land border with Saudi Arabia has also been blocked as a result.