MOGADISHU, Somalia (AP) — A suicide car bomber detonated an explosives-laden vehicle near a restaurant in the Somali capital Thursday, killing himself and injuring three others, a Somali police officer said.

The attacker detonated the massive bomb after his car overturned during a high-speed chase by police near the presidential palace in Mogadishu. Only the bomber died in the blast in the heavily guarded area where there are key government institutions, said Capt. Mohamed Hussein.

The attacker's exact target was not clear, but Hussein said he believed the bomber was trying to ram his vehicle into a car carrying a senior police commander. The commander's bodyguards were injured in the attack, he said.

There was no immediate claim of responsibility for the blast, but Somalia's Islamic extremist group al-Shabab frequently carries out such attacks.

A surge in al-Shabab attacks could further delay the country's presidential elections, which have been postponed several times and are now set for Dec. 28.

Al-Shabab opposes the elections. Despite being ousted from most of its key strongholds in south and central Somalia, al-Shabab continues to launch deadly guerrilla attacks against the Somali government and African Union forces across large parts of the horn of Africa nation.