The United States carried out retaliatory strikes on Friday in Iraq and Syria against facilities linked to Iran's Revolutionary Guards and the militias they back, four U.S. officials said, after a deadly attack in Jordan that killed three U.S. troops and injured some 40 others. The strikes are believed to be just the first in a multi-tiered response by President Joe Biden's administration in response to the attack last weekend carried out by Iran-backed militants. While the U.S. strikes did not target any locations inside Iran, they are likely to increase concern about tensions in the Middle East spiraling from Israel's more than three-month-old war with Palestinian Hamas militants in Gaza.