Dozens of protesters stormed the compound of the United States embassy in Iraq on Tuesday in response to American airstrikes that killed dozens of fighters from an Iran-backed militia group.

American fighter jets on Sunday bombed weapons depots in Iraq and Syria that the U.S. said were linked with a group called Kataeb Hezbollah, which it blames for attacks on coalition bases in recent months.

At least 25 militia fighters were killed in the airstrikes, and on Tuesday a large crowd gathered after funerals for some of the dead and marched on the U.S. Embassy in Baghdad’s heavily fortified Green Zone.

They chanted “Down, Down USA!” while hurling water bottles and smashing security cameras, according to The Associated Press. An AP reporter at the scene saw flames rising from inside the compound and at least three U.S. soldiers on the roof of the main building inside embassy.

Guards inside the embassy used tear gas to try and prevent demonstrators from moving towards main buildings inside the compound, an Iraqi security source told NBC News on condition of anonymity.

At least 10 demonstrators were injured by live bullets and tear gas, according to the Popular Mobilization Forces, an umbrella group for the militias recognized by the Iraqi government.

The U.S. blames Kataeb Hezbollah for 11 attacks on bases used by the U.S.-led coalition over the past two months. The latest of these came on Friday, when a rocket attack killed a U.S. contractor and injured four other American service members.

The U.S. airstrikes have been met with an angry reaction from both Iran and Iraq.

The U.S. has some 5,000 troops in Iraq train and assist government troops in the fight against the Islamic State militant group. But the Iraqi government is also allied with a powerful network of militia groups, many of which are backed by or linked to Tehran.

Tehran called the U.S. airstrikes “terrorism” and Iraq called them a “violation” of its sovereignty. The militia targeted has vowed to respond.