(CNN) Amnesty International accused the US military on Tuesday of causing civilian casualties in a series of airstrikes in Somalia in 2017 and 2018, claims the US military denies.

The strikes in question came after President Donald Trump eased restrictions on the use of airpower in the East African nation.

US Africa Command, which oversees US military operations on the continent, firmly rejected the allegations, saying it has made efforts to ensure the safety of civilians and that it had reviewed the allegations and found no evidence to support them.

While Africa Command acknowledged conducting strikes in four of the locations and times identified in the report, it said it had reviewed the allegations and found the targets to have been affiliated with Al-Shabaab.

The Amnesty International report, released Tuesday night, alleges that 14 civilians were killed and eight were injured in a series of five airstrikes in the Lower Shabelle region of Somalia, a hotbed of Al-Shabaab militant activity.

Because of the security situation in the targeted area neither the Amnesty team nor the US military was able to do on-the-ground investigations into the results of the strikes.

"In the incidents presented in this report, civilians were killed and injured in attacks that may have violated international humanitarian law ... and could, in some cases, constitute war crimes," the report alleges, saying that several of the strikes had killed civilians who were near suspected Al-Shabaab militants.

The dates of the strikes range from October 2017 to December 2018.

"We take all allegations of civilian casualties seriously regardless of their origin," Africa Command said in a statement following the report's release, saying it had reviewed Amnesty's allegations prior to the report's publication.

"Our assessments found that no AFRICOM airstrike resulted in any civilian casualty or injury. Our assessments are based on post-strike analysis using intelligence methods not available to non-military organizations," the statement added.

Africa Command said that many of the allegations involved claims made by media outlets affiliated with Al-Shabaab, and that "it is in the interest of the terrorist group al-Shabaab to untruthfully claim civilian casualties. It is also in the interest of al-Shabaab to coerce community members to make untrue claims."

Maj. Gen. Gregg Olson, Africa Command director of operations, said in a conference call with reporters, "I'm not going to go into the specifics of the sources and methods that we use to characterize targets but I will tell you that it is a process that unfolds over time as we look at things like pattern of life, as we look at things like all source intelligence and then fuse together a picture that provides us a standard that is appropriate under international humanitarian law. And that accounts for the information available at the site before any decision to strike is made."

There has been a significant increase in US airstrikes in Somalia since Trump authorized the military to carry out precision strikes targeting Al-Shabaab in March 2017 in an effort to bolster the Somali government. Prior to that, the US military was authorized to conduct airstrikes only in defense of advisers on the ground.

At least 252 fighters from the al Qaeda-affiliated Al-Shabaab have been killed in 28 airstrikes so far in 2019, with no civilian deaths, according to figures released by US Africa Command.

The most recent strike took place Tuesday in the vicinity of Awdheegle, Lower Shabelle Region, and killed three "terrorists," according to a statement Tuesday by Africa Command.

The statement said the US military was aware of reports alleging civilian casualties from Tuesday's airstrike and that as with every allegation, Africa Command "will review any information it has about the incident, including any relevant information provided by third parties."

In 2018, the US conducted 47 airstrikes targeting Al-Shabaab, killing about 338 militants. In 2017, the US carried out 35 airstrikes, and in 2016 it conducted 15.

US defense officials have told CNN that the recent increase in the pace of strikes is due to successes that local Somali security forces have been having in combating Al-Shabaab.

The US military estimates that Al-Shabaab commands over 4,000 fighters.

The US has 500 to 600 troops in Somalia, primarily in advisory roles.