A large group of protesters, angry over American airstrikes targeting an Iranian-supported militia,attacked the outer edge of the U.S. Embassy in Baghdad on Tuesday.The protesters threw stones, set fires and damaged property and vehicles.Security forces fired tear gas at the group in an effort to bring the situation under control.American President Donald Trump blamed Iran for the attack. Writing on Twitter,he said: "Iran killed an American contractor, wounding many.We strongly responded, and always will.Now Iran is orchestrating an attack on the U.S. Embassy in Iraq.They will be held fully responsible.In addition, we expect Iraq to use its forces to protect the Embassy, and so notified!"The protesters were voicing anger over U.S. airstrikes that took place on Sunday killing at least 25 people.U.S. officials said the strikes answered a rocket attackon an Iraqi military base on Friday that killed a U.S. defense contract worker.The raids targeted areas held by a militia group called Kataeb Hezbollah.The group has ties to Iran, but is separate from the group Hezbollah in Lebanon.The Iraqi government called the U.S. airstrikes a "flagrant violation" of Iraq's sovereignty.The Associated Press reported that Iraqi security forcesmade no effort to stop the protesters as they marched toward the embassy in the Green Zone.The protesters, many of them in militia uniforms, shouted "Death to America."They threw stones over the embassy walls and set fire to three trailers used by security guards outside the wall.Others smashed the gates used by cars to enter the embassyand came about 200 meters away from the main building.A group of U.S. soldiers were seen on the roof of the main building,pointing their guns at the protesters.Hours after the violence started, about 30 Iraqi soldiers arrived near the embassy to help control the crowd.The AP reported that the U.S. Ambassador to Iraq was traveling outside of the country before Tuesday's attack took place.Some embassy staff left through a rear gate and others remained inside "safe" areas within the embassy.By Tuesday evening, the protesters set up tents outside the embassy.Yellow flags belonging to Iran-backed Shiite militias were flown and anti-U.S. graffiti painted on the wall.A spokesman for Kataeb Hezbollah said the sit-in outside the embassy will continue"until American troops leave Iraq and the embassy is closed."More than 5,000 U.S. troops are stationed in Iraq to support local forces in the fight against the Islamic State.