Somali Islamist group al-Shabab has confirmed the US had bombed an area it controlled but says the figure of more than 150 casualties is an exaggeration.
The Pentagon had said it launched air strikes on a training facility on Saturday that had killed 150 fighters with the al-Qaeda-linked group in the Horn of Africa nation.
"The US bombed an area controlled by al Shabab. But they exaggerated the figure of casualties. We never gather 100 fighters in one spot for security reasons. We know the sky is full of planes," the group's military spokesman Sheikh Abdiasis Abu Musab told Reuters on Tuesday.
He did not give a casualty figure or offer further details about the raid.
The strike, using both planes and unmanned MQ-9 Reaper drones, targeted al-Shabab's "Raso" training camp, a facility about 200km north of the capital Mogadishu, the Pentagon said.
The US military had been monitoring the camp for several weeks before the strike and had gathered intelligence, including about an imminent threat posed by those in the camp to US forces and African Union peacekeepers, officials said.
US Air Force secretary Deborah Lee James described the strike as "defensive" in nature.
The African Union AMISOM force, alongside the Somali army, launched a campaign last year that drove al-Shabab out of its major strongholds. But the group, which wants to topple Somalia's Western-backed government, continues to launch raids.
In the past two weeks, its fighters have launched mortar attacks near the presidential palace in Mogadishu, blown up a car bomb near a busy park in the capital, and set off twin blasts in a town northwest of the capital. Dozens of people have been killed.
The group, which seeks to impose its strict version of Islamic law, had controlled Mogadishu until 2011, when the African forces drove it out.