A Somali police officer says at least four people are wounded after a suicide bomber detonated an explosives-laden vehicle outside the compound of a district headquarters in Somalia's capital.
Capt Mohamed Hussein says the bomber tried to speed through a checkpoint but was stopped by security forces, prompting him to detonate the vehicle near the gate of Howlwadag district headquarters.
He says the wounded are mostly young students at a nearby Islamic school.
Officials warn there could be more casualties as the blast pulled down nearby buildings including a mosque.
There is no immediate claim of responsibility for the explosion, which shattered a period of calm in seaside Mogadishu.
The al-Shabab extremist group often targets the capital.