At least 13 people have been killed in two car bomb attacks near a United Nations peacekeeping zone and the international airport serving Mogadishu, the capital of Somalia.

According to reports, a suicide car bomb was detonated at a checkpoint to the African Union Mission in Somalia, or AMISOM, base near the airport. The base is in the secure “green zone” of Mogadishu, where United Nations offices and foreign embassies are located.

Another blast hit the airport’s perimeter wall.

Among those dead are believed to be security guards.

The militant Islamist group al-Shabaab claimed responsibility for the blasts, saying they were targeting the African Union mission’s headquarters. The group has been carrying out frequent attacks in Somalia in an attempt to oust the UN-backed government.

The AMISOM base was previously infiltrated by al-Shabaab in December 2014.

The Somali government and AU forces are working together to fight al-Shabaab around the East African country.

The AU mission in Somalia condemned “these senseless attacks that aim to disrupt and cripple the lives of ordinary Somalis” in a statement on Twitter.

The National Security Council condemned the attacks, reemphasizing the United States’ backing of Somalia.

“We remain committed to helping Somalia progress along a path towards peace and prosperity and the defeat of terrorist groups, including al-Shabaab,” NSC Spokesman Ned Price said in a statement.