I answered a question very similar to this in this thread.

TL;DR- Linguists and Anthropologists say that there was a bantu presence on the Benadir coast when Mogadishu was founded. The presence of Arab and Persian influence, similarities in coinage and architecture, and Mogadishu's role in founding the swahili city state of Sofala all strengthen the argument that Mogadishu was an integral part of the coastal Swahili culture.