MOGADISHU, Somalia — Al-Qaida-linked militants in Somalia have pulled out of a key city after it was invaded by Kenyan troops.

Residents in Kismayo said they awoke Saturday to empty police and government headquarters, which were soon looted by residents. Al-Shabab said on its Twitter feed it pulled out of Kismayo after controlling the city for five years.

Col. Cyrus Oguna, a spokesman for the Kenyan military, which invaded Kismayo on Friday, said ground troops were still verifying whether al-Shabab had withdrawn.

Kenyan troops are in the northern part of Kismayo and working their way south. Oguna said a battle overnight killed five al-Shabab fighters.

Kismayo, an important economic center for the insurgents, was the last major stronghold controlled by al-Shabab.

The group was forced out of Mogadishu in August 2011.