In its second set of mass-casualty drone strikes this month, the Pentagon has killed roughly 200 people in Yemen and Somalia.

On Tuesday, Pentagon spokesman Peter Cook confirmed that the US military had bombed a "training camp" used by "more than 70 AQAP [al-Qaida in the Arabian Peninsula] terrorists."

"We continue to assess the results of the operation, but our initial assessment is that dozens of AQAP fighters have been removed from the battlefield," the spokesman said in a statement.

The Pentagon has not revealed the specific location of the camp and has not released details on possible civilian deaths.

According to local Yemeni medics and officials, at least 50 were killed and another 30 wounded.

"The planes struck as al-Qaeda people stood in line to receive their dinner meal," said one official, speaking on condition of anonymity.

This is the second mass-casualty airstrike conducted by the US military this month. On March 5, the Pentagon killed an estimated 150 people, targeting an al-Shabaab training camp in Somalia.

"We know they were going to be departing the camp and that they posed an imminent threat to US and to Amisom, African Union mission in Somalia forces, that are in Somalia," a Pentagon spokesman said at the time.

"Their removal will degrade al-Shabaab’s ability to meet the group’s objectives in Somalia, which include recruiting new members, establishing bases and planning attacks on US and Amisom forces there."

The spokesman assured reporters that there were no civilian casualties.

The strikes are the latest example of the Obama administration's reliance on drone warfare. The program’s lack of transparency has been heavily criticized by rights groups.

"Little progress has been made during the past year and a half to enact reforms that establish a more sensible US drone policy consistent with America’s long-term security and economic interests," reads a report from US think tank Stimson Center.

"The lack of a clear drone policy risks leaving a legacy on drone use that is based on secrecy and a lack of accountability that undermines efforts to support the international rule of law."

While the Pentagon downplays civilians deaths, data collected by the Bureau of Investigative Journalism shows that US drone strikes have killed roughly 1,000 civilians in Afghanistan, Pakistan, Somalia, and Yemen over the past 10 years.