A police chief says that a masked gunman believed to be a member of an al-Qaida-linked Somalia militant group stormed a hotel in a Kenyan city near the border with Somalia and opened fire with an assault rifle, killing nine people.

Vitalis Okumu said Friday that the Thursday night attack could have been in retaliation for military activity carried out by African Union forces, which Kenya is a part of, against al-Shabab militants in Somalia.

Garissa lies near the border with Somalia and has suffered a string of attacks over the last 18 months by gunmen believed to be associated with al-Shabab.