On Wednesday, three servicemen, including two Americans, were killed when the base was attacked BAGHDAD: A barrage of rockets hit a base housing US and other coalition troops north of Baghdad, Iraqi security officials said Saturday, just days after a similar attack killed three servicemen, including two Americans. The attack was unusual because it occured during the day. Previous assaults on military bases housing US troops typically occurred overnight. Two of the three US troops wounded in the latest rocket attack in Iraq are seriously injured and are being treated at a military hospital in Baghdad, the Pentagon said on Saturday, in its first confirmation that Americans were injured. Pentagon spokesman Jonathan Hoffman declined to speculate on potential US responses but, in a statement, cited Defense Secretary Mark Esper"s warning last week: "You cannot attack and wound American Service Members and get away with it, we will hold them to account." Hoffman added that Iraqi security forces had made an initial arrest and added the United States was assisting with the investigation into the attack, the second in less than a week at Camp Taji, north of Baghdad. Iraqi forces were also injured. An earlier attack against Camp Taji on Wednesday prompted American airstrikes Friday against what US officials said were mainly weapons facilities belonging to Kataib Hezbollah, the Iran-backed militia group believed to be responsible. However, Iraq’s military said those airstrikes killed five security force members and a civilian. Iran-backed Shiite militia groups vowed to exact revenge for Friday’s US strikes, signalling another cycle of tit-for-tat violence between Washington and Tehran that could play out inside Iraq. Wednesday’s attack on Camp Taji was the deadliest to target US troops in Iraq since a late December rocket attack on an Iraqi base. That attack killed a US contractor and set in motion a series of attacks that brought Iraq to the brink of war. After the contractor was killed, American airstrikes targeting the Kataib Hezbollah led to protests at the US Embassy in Baghdad. A US drone strike in Baghdad then killed Iranian Gen. Qassem Soleimani, a top commander responsible for expeditionary operations across the wider Mideast. Iran struck back with a ballistic missile attack on US forces in Iraq, the Islamic Republic’s most direct assault on America since the 1979 seizing of the US Embassy in Tehran. The US and Iran stepped stepped back from further attacks after the Soleimani incident. A senior US official said in late January, when US-Iran tensions had cooled, that the killing of Americans constituted a red line that could spark more violence.