A barrage of rockets has hit an Iraqi military base housing US-led coalition troops for the second time this week, security officials said.

Three coalition service personnel – a British woman and two Americans – were killed in the first attack on Camp Taji on Wednesday.

It was the deadliest attack on coalition troops in Iraq since a late December rocket attack on an Iraqi base that killed a US contractor and set in motion a series of tit-for-tat attacks that brought Iraq to the brink of war.

In retaliation, the US launched a series of air strikes on militia bases across Iraq’s south, killing five Iraqi security forces and a civilian.

Lance Corporal Brodie Gillon
Lance Corporal Brodie Gillon (Ministry of Defence/PA)

Lance Corporal Brodie Gillon, who served as a reserve with the Scottish and North Irish Yeomanry, died in the attack on Wednesday after a dozen missiles were fired at the camp north of Baghdad.

At least two Iraqi soldiers were wounded in the latest attack, according to the Iraqi officials.

They said more than a dozen rockets landed inside the base, some striking the coalition quarters and others falling on a runway used by Iraqi forces.

The attack was unusual because it occurred during the day. Previous assaults on military bases housing US troops typically occurred overnight.

The earlier attack against Camp Taji prompted US air strikes on 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 air strikes killed five security force members and a civilian.

Scenes of US air strikes
(Department of Defence/AP)

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.

After the contractor was killed in December, American air strikes targeting the Kataib Hezbollah led to protests at the US embassy in Baghdad.

A US drone strike in the capital then killed Iranian General Qassem Soleimani, a senior commander responsible for expeditionary operations across the wider Middle East.

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.