U.S. forces in Iraq and Syria have been attacked with drones or rockets at least 17 times in recent days, including on Thursday, according to U.S. officials.
"I can tell you that we are aware of an attack today against U.S. forces," Pentagon press secretary Brigadier General Pat Ryder told reporters, referring to the air base in Irbil, Iraq. "It was unsuccessful. No casualties. Some minor damage to infrastructure. But again, we will make sure that we're able to update that information. I'm not tracking a second one at this point in time, but again, as that information comes in."
Two U.S. officials, speaking on condition of anonymity because of the sensitivity of the attacks, told VOA that a drone landed on the base in Irbil but did not explode.
Hours later, another drone exploded outside the base, causing no injuries or damage, according to the officials.
Another attack on Thursday was reported in northeastern Syria, with two rounds of indirect fire near a base in al-Shaddadi, an official told VOA.
Ryder reiterated previous comments blaming Iranian-backed proxies for the near daily attacks on U.S. forces.
"We know that these are Iranian-backed militia groups that are supported by Iran and, of course, we hold Iran responsible for these groups," Ryder said.
Asked whether the United States planned to respond to the attacks, Ryder told reporters the military would "do something at a time and place of our choosing, should we choose to do so."
"We will always reserve the right to self-defense, and we will take all necessary actions to ensure that our forces are protected and that our interests overseas are protected," Ryder said.
Officials have raised concerns about the prospect of "more significant escalation" against U.S. military forces and personnel in the region from Iranian proxy groups.
The attacks have resulted in 17 minor injuries to Americans in Syria and four minor injuries to American personnel in Iraq, with U.S. officials continuing to monitor any potential traumatic brain injuries, Ryder said.
One U.S. contractor at Al-Asad Air Base in Iraq suffered a cardiac episode while sheltering in place during a false alarm for an air attack and died.
In addition to the three attacks on Thursday, officials said three rockets targeted a base that houses U.S. forces near Kharab al-Jir, Syria, on Wednesday, causing no injuries.
US increasing protection in region
About 900 troops have either deployed or are in the process of deploying from the United States to the Middle East to increase force protection. These units include a Terminal High Altitude Area Defense battery from Fort Bliss, Patriot batteries from Fort Sill and Patriot and Avenger batteries from Fort Liberty.
U.S. Defense Secretary Lloyd Austin placed an undisclosed number of troops on prepare-to-deploy orders Saturday.
These moves came after Austin had placed more than 2,000 military personnel on heightened alert with a prepare-to-deploy order earlier last week.
