A US military base used to launch drones and a European military convoy have been hit in separate attacks in Somalia.

A Reuters journalist saw a seriously damaged armoured vehicle bearing a small Italian flag sticker in the capital, Mogadishu, on Monday. It was unclear if there were any casualties.

Italy’s defence ministry said in a statement that an Italian military convoy had been hit by an explosion. No injuries had been reported so far, the ministry said.

Also on Monday, a base operated by US special forces in the town of Baledogle was hit by a bomb attack followed by small arms fire, a security source told Reuters.

The insurgent group al-Shabaab claimed responsibility for the attack. “In the early hours of Monday morning, an elite unit of soldiers from Harakat al-Shabaab al-Mujahideen Martyrdom Brigade launched a daring raid on the US military base,” the group’s press release said. “After breaching the perimeters of the heavily fortified base, the mujahideen (holy warriors) stormed the military complex, engaging the crusaders in an intense firefight.”

The base is in the Lower Shabelle region, about 60 miles (100km) west of Mogadishu. It is a launching site for US drone operations against al-Shaabab, an al-Qaida-linked group that controls large parts of Somalia, as well as Islamic State in Somalia.

Mohamed Adan, a Somali elder who was close to the scene of the attack, told Agence France-Presse by phone: “Two heavy explosions occurred, the first one bigger than the other. There was also a heavy exchange of gunfire after the blasts but we don’t know about the details.”

In the other incident, a security official said EU advisers training the Somali national army were attacked by a car bomb in Mogadishu.

“There was a car bomb targeting the EU military advisers along the industrial road. A vehicle loaded with explosive was rammed on to one of the convoy vehicles and there are casualties,” said Omar Abikar, a Somali security officer.

Italy’s vice-minister of foreign affairs, Emanuela Del Re, said on Twitter that Italian soldiers had been targeted in the attack. “Very worried for the explosion at the passage of Italian soldiers EUTM in Somalia,” she said, referring to the EU training mission in Somalia.

Site Intelligence, which monitors jihadist activities worldwide, said al-Shabaab had claimed responsibility for both attacks. They are the latest in a long line of bombings and assaults claimed by the group.

The jihadists were driven out of Mogadishu in 2011 by government forces backed by 20,000 African Union peacekeepers. But they still carry out attacks including suicide bombings against government targets.

Agence France-Presse contributed to this report