The United States is sending 1,000 additional troops to the Middle East, amid rising tensions between the U.S. and Iran. The decision follows last week’s attack on two tankers in the Gulf of Oman that the U.S. blamed on Tehran, with the Pentagon releasing new images on Monday that officials said show Iranian Islamic Revolutionary Guard Corps (IRGC) members removing an unexploded mine from one of the ship’s hulls.

“In response to a request from the U.S. Central Command (CENTCOM) for additional forces, and with the advice of the Chairman of the Joint Chiefs of Staff and in consultation with the White House, I have authorized approximately 1,000 additional troops for defensive purposes to address air, naval, and ground-based threats in the Middle East,” acting Defense Secretary Patrick Shanahan said in a statement on Monday.

The U.S. has already accelerated the deployment to the Middle East of the USS Abraham Lincoln aircraft carrier strike group and sent B-52 bombers after what it said were credible threats by Iran against U.S. forces and interests in the region. Since then, the U.S. has sent an additional 1,500 troops and increased defensive capabilities to continue to help deter Iran.

“The recent Iranian attacks validate the reliable, credible intelligence we have received on hostile behavior by Iranian forces and their proxy groups that threaten United States personnel and interests across the region,” Shanahan said.

“The United States does not seek conflict with Iran,” the statement continued. “The action today is being taken to ensure the safety and welfare of our military personnel working throughout the region and to protect our national interests. We will continue to monitor the situation diligently and make adjustments to force levels as necessary given intelligence reporting and credible threats.”

Iran attempted to shoot down a U.S. drone that was surveilling the attack on one of two tankers hit in the Gulf of Oman last week, CENTCOM said. The attempt missed the MQ-9 Reaper by “approximately one kilometer.”

The U.S. has also blamed Iran for an attack on four commercial vessels off the coast of the United Arab Emirates in May.

In an effort to bolster its public case against Iran, the Pentagon on Monday released new photos that officials said show that members of Tehran’s Revolutionary Guard were responsible for attacks last week on two oil tankers near the Persian Gulf.

The images, many taken from a Navy helicopter, show what the Pentagon said were Iranian forces removing an unexploded mine from the side of the Japanese-owned Kokuka Courageous oil tanker in the Gulf of Oman.

Officials last week said the move appeared to be an attempt to remove forensic evidence from the scene of the attack. But it’s not clear if examination of the mine would have made it definitively clear that the device was planted by the IRGC.

Other photos show a large hole on the side of the Courageous, above the water line, that officials say appears to have been caused by another similar mine.

The release of the photos came as the U.S. works this week to convince members of Congress and allies that the accusations against Tehran are true. Iran has denied involvement in the tanker attacks and has accused America of promoting an “Iranophobic” campaign. Tehran, however, has repeatedly threatened to close the vital Strait of Hormuz, through which 20% of the world’s oil flows.

Secretary of State Mike Pompeo said he made a number of calls Sunday and Monday to international leaders, trying to convince them that keeping the Strait of Hormuz safe and open is a problem they all must deal with.

Relations between the U.S. and Iran have deteriorated in recent months, as the Trump administration restored crippling sanctions and designated the Revolutionary Guard as a foreign terrorist organization.

That increased pressure preceded a string of attacks that the U.S. has blamed on Iran. In late May, four oil tankers off the coast of the United Arab Emirates were attacked with what appeared to be mines, and there was a rocket attack in Baghdad. Last week, similar attacks were launched against the Courageous and the Norwegian-owned MT Front Altair in the Gulf of Oman.

The U.S. military has also accused Iranian Revolutionary Guard troops of trying but failing to shoot down a U.S. drone to disrupt surveillance of the tankers during the attacks.

(AP)