The USS Abraham Lincoln aircraft carrier and three accompanying warships have arrived in the Middle East, a move that renews the possibility that President Donald Trump could order military strikes against Iran over its crackdown on anti-government protesters.

The carrier, along with three destroyers, "is currently deployed to the Middle East to promote regional security and stability," U.S. Central Command said Monday on social media.

The strike group was in the Indian Ocean, Central Command said, and not in the Arabian Sea, which borders Iran. It will bring thousands of additional service members to the region, which has not had a U.S. aircraft carrier since the USS Gerald R. Ford was ordered in October to sail to the Caribbean as part of a pressure campaign on then-Venezuelan President Nicolás Maduro.

Trump told reporters last week that the ships were sent to the region "just in case." "We have a massive fleet heading in that direction, and maybe we won't have to use it," he said.

Trump earlier had threatened military action if Iran carried out mass executions of prisoners or killed peaceful demonstrators during a crackdown on protests that began in late December. At least 5,973 people have been killed and more than 41,800 detained, according to activists. The official Iranian death toll is far lower, at 3,117 dead.