US forces have "dramatically increased" the number of air strikes in Somalia with several civilians killed by the powerful missiles, Amnesty International said Wednesday, reports denied by the military.
Amnesty calculates that there have been more than 100 strikes by US drones and manned aircraft in the past two years, more than the number of US airstrikes in Yemen and Libya combined during the same period.
Researchers who investigated five airstrikes in detail reported at least 14 civilians had been killed -- raising fears the total dead in the scores of attacks may be far higher -- even though the US military insists there have been no civilian deaths.
"The attacks appear to have violated international humanitarian law, and some may amount to war crimes," Amnesty said in the report, titled "The Hidden US War in Somalia".
The study is based on 150 interviews including witnesses, family members of those killed and security experts.
Their reports were corroborated by satellite imagery, photographs of the deep craters of the explosions, as well as munition fragments collected from the sites.
US strikes, which included missiles fired by manned aircraft as well as drones, targeted Somalia's Al-Qaeda linked insurgents, Al-Shabaab.
The US military said it had carried out 110 airstrikes in Somalia since June 2017, killing 800 people. But it insisted they had all been legitimate targets as members of Al-Shabaab, and that the Amnesty report was incorrect.
"Since June 2017, AFRICOM conducted 110 airstrikes in Somalia, eliminating more than 800 terrorists," US Africa Command said in a statement, adding that "our assessments found that no AFRICOM airstrike resulted in any civilian casualty or injury."
AFRICOM added that it was "in the interest of the terrorist group al-Shabaab to untruthfully claim civilian casualties."
Amnesty said it had carried out detailed investigations into five attacks, where they found that at least 14 civilians were killed.
"The civilian death toll we've uncovered in just a handful of strikes suggests the shroud of secrecy surrounding the US role in Somalia's war is actually a smokescreen for impunity," said Brian Castner, Amnesty's military expert.
"Our findings directly contradict the US military's mantra of zero civilian casualties in Somalia."
The findings were shown to AFRICOM but the US military denied civilians had been killed, Amnesty said.
US strikes in Somalia surged in April 2017, after President Donald Trump declared southern Somalia an "area of active hostilities", Amnesty said.
According to Amnesty, US forces carried out 34 strikes in 2017 following Trump's declaration, more than in all the previous five years since 2012 combined.
In 2018, the number of strikes rose to 47 while there have been 24 already in the first two months of 2019 alone.
The Shabaab have been waging an insurgency against Somalia's foreign-backed government for over a decade, and while it has lost ground, continues to stage deadly attacks in the country as well as neighbouring nations such as Kenya.