The United Arab Emirates, a key member of the Saudi-led coalition fighting in Yemen, is scaling back its military presence there as worsening US-Iran tensions threaten security closer to home, Reuters reported four western diplomatic sources saying.

The UAE has pulled some troops from the southern port of Aden and Yemen’s western coast, two of the diplomats said, areas where the Gulf state has built up and armed local forces who are leading the battle against the Iran-aligned Houthi group along the Red Sea coast.

Three of the diplomats said Abu Dhabi preferred to have its forces and equipment on hand should tension between the United States and Iran escalate further after attacks on oil tankers in the Gulf and Tehran’s downing of a US unmanned drone.

“It is true that there have been some troop movements … but it is not a redeployment from Yemen,” a senior Emirati official told Reuters, adding that the UAE remains fully committed to the military coalition and “will not leave a vacuum” in Yemen.

The official would not provide details on the movements, the numbers involved or specify whether it was happening inside or outside Yemen, where the alliance intervened in 2015 to try to restore the government ousted from power by the Houthis.

It is not clear how many Emirati forces are in Yemen. One Western diplomat said the UAE withdrew “a lot” of forces from the Arabian Peninsula nation over the last three weeks.

Asked whether tensions with Iran were behind the move, the Emirati official said the decision was more related to a holding ceasefire in Yemen’s main port city of Hudaydah, now held by the Houthis, under a UN-led peace pact reached last December.

“This is a natural progression,” the official said, reiterating the UAE’s support for UN efforts to implement the deal in Hudaydah, a lifeline for millions of Yemenis, to pave the way for talks to end the war.