MOGADISHU (Reuters) - African Union peacekeepers did not help in the arrest of a former al Shabaab leader that led to clashes in which 11 people were killed, the AU force said, following a report that Ethiopian members of the force had been involved.

At the same time, Somalia’s national parliament speaker, Mohamed Mursal Abdirahman, called for the release of Mukhtar Robow and the postponement of regional presidential elections in South West region, where Robow is vying for the post.

Somalia’s Internal Security Ministry said it arrested Robow on Thursday, accusing him of bringing Islamist militants and weapons back to Baidoa, the capital of South West region.

Robow’s spokesman had said he was beaten by Ethiopian troops, who are part of the African Union peacekeeping force in Somalia, in the course of his arrest. Local elders and residents had also said Ethiopian troops had helped with the arrest.

“AMISOM had no part in the arrest of Mr. Robow and his subsequent transfer to Mogadishu,” it said, adding that the peacekeeping force will continue to respect the sovereignty of the people and the government of Somalia.

Robow, a former prominent al Shabaab insurgent and group spokesman, publicly renounced violence and recognized federal authority in August 2017.

His arrest triggered clashes between security forces and his supporters on Thursday and Friday that killed 11 people, including a regional government lawmaker.

The regional elections are a critical point in a growing power struggle between the U.S.-backed central government and regions where al Shabaab militants retain a presence following a long civil war.

“The South West election committee should postpone the election until there is a calm situation, free and fair, conducive for the election to take place,” Abdirahman said in a statement. “The arrested candidate should quickly be released and allowed to return peacefully to his area.”