Somalia's al Shabaab Islamist group rammed a military base with a suicide truck bomb, shot dead an intelligence officer and killed 12 people in a Kenyan border town in a series of strikes over 24 hours, the militants said on Tuesday.

The attacks mark the build up to elections in coming weeks for the Somali parliament, which will in turn pick a new president to continue slow reconstruction efforts in a nation racked by more than two decades of conflict.

Al Shabaab spokesman Abdiasis Abu Musab said the group was behind a truck bomb that rammed into an AMISOM base in the Somali town of Beledweyne, north of Mogadishu. He said 17 soldiers from Djibouti were killed in the attack.

The al Shabaab spokesman also said the group shot senior intelligence officer Colonel Abdiasis Araye as he walked to a mosque late on Monday in Mogadishu.

He also said al Shabaab was behind Tuesday's early morning attack on a hotel in Kenya's northeastern Mandera town, killing at least 12 people according to police and 15 people according to al Shabaab's account. 

The group, which once ruled much of Somalia, wants to topple the Western-backed government in Mogadishu and drive out African AMISOM peacekeepers made up of soldiers from Kenya, Djibouti, Uganda, Ethiopia and other African nations.

Read more: Reuters