Somalia's government fired the police and intelligence chiefs the day after Islamic militants attacked the heavily guarded presidential palace in the capital, Mogadishu, the information minister said Wednesday.

Government troops and African Union peacekeepers repelled the attack and no government official was hurt, Mustafa Dhuhulow said. Three of four militants were shot dead by soldiers, after they forced their way into the presidential palace late Tuesday, sparking an exchange of gunfire, he said. The fourth militant was wounded.

Dhuhulow told reporters Wednesday that police commander Abdihakim Saaid and intelligence chief Bashir Gobe had been replaced immediately.

A new minister for national security was also appointed in changes announced by Somali Prime Minister Abdiweli Sheikh Ahmed, who was inside the palace when the attack happened.

The presidential compound, which also houses several government offices, has been the subject of many attacks by al-Qaida-linked militants over the years. It is considered one of the safest places in Mogadishu because of the tight security presence.

The Islamic extremist group al-Shabab claimed responsibility for the attack. The militants have vowed to step up attacks during the Muslim holy month of Ramadan.

The attack was the second assault on the presidential palace this year, and it and it marked the first time militants have been able to breach the compound and take offensive positions inside. The palace is protected by government troops and African Union peacekeepers who helped to drive the al-Shabab militants out of their bases in Mogadishu in 2011.

Somalia has been trying to rebuild following years of political instability and civil strife since 1991, when the dictator Siad Barre was ousted from power.

President Hassan Sheikh Mohamud's Western-backed government has promised to put the country on a path toward democracy and economic progress, despite regular attacks by Islamic militants.