LONDON: The UK Ministry of Defense has refused to comment on whether it investigated a targeted drone strike on a Daesh leader in Syria that reportedly led to civilian injuries, The Guardian reported.

The strike by the Royal Air Force in Al-Bab, northern Syria, in December, involved a Reaper drone targeting a “leading Daesh member,” Defense Secretary Ben Wallace said on Monday.

Though the strike resulted in Abu Yasser Al-Yemeni, a local Daesh leader, being taken to hospital, two civilians were also reported injured in the attack that involved two Hellfire missiles launched by the drone.

In its war against Daesh since 2014, the RAF has carried out more than 5,500 combat missions and fired in excess of 4,300 missiles but has only acknowledged the death of a single civilian.

However, the Inherent Resolve coalition against Daesh, the international military grouping led by the US, has said that 1,437 civilians have died in air assaults against Daesh targets.

The strike in December targeted Al-Yemeni because of his involvement in “chemical and biological weapons,” Wallace said, adding that drone operators had “minimized potential risk to civilians.”

The target was transported to hospital in the wake of the attack amid “secrecy regarding his fate,” Syria’s Observatory for Human Rights said, adding that state television reported injuries to a woman and child.

UK non-governmental organization Drone Wars requested information from the Ministry of Defense over whether it had investigated the reports of civilian injuries following the attack.

In a written response, the ministry refused to comment on the matter.

Drone Wars founder Chris Cole said: “Refusing to even disclose whether the UK is undertaking an investigation into reports of civilian casualties arising from its drone-targeted killing is also simply unacceptable.”

He added that although Daesh remained a “serious terror threat” in the UK, it was “far from clear” that the group’s leaders were “a threat to the UK or should be subject to UK military force.”