No justification can redeem acts such as the Garissa massacre. Such clarity is a boon when it can be hard to sort freedom fighters from terrorists.
Some welcome the security move but Somalia's president says a barrier can't stop an ideology.
Since other islamic terrorist groups are on the rise, al-Shabab struggles in the public relations department.
Kenyans are fleeing the Muslim-dominated north after al-Shabab hijacked a bus and executed 28 people for failing to prove they were Muslims.
The Somali militants say they staged an attack in Kenya in which 28 people were shot dead.
Sheikh Ahmad Umar Abu Ubaidah has replaced slain Al-Shabab leader Ahmed Godane, who was killed in a US air strike.
Somalia's al-Shabab rebels have carried out a major attack against intelligence headquarters and a detention facility in central Mogadishu.
Despite the US and EU’s thoughts that Somalia is a country that is making steady progress, the facts on the ground show that Somalia is still a mess.
Gunmen believed to be from Somali Islamist militant group al-Shabab have struck again in Kenya, killing at least 29 people.
Beyond signing pledges to co-operate in fighting Islamic extremists like Boko Haram and al-Shabab, no real strategy is in place.
Massacres on the Kenyan coast have once again brought political rivalries to the fore.
Tension runs high as country's president blames al-Shabab attacks on 'local political networks'.
Islamist militants have killed at least 15 people and torched houses in a second night of attacks on Kenya's coast.
Al-Shabab says it killed at least 49 people in Mpeketoni in response to the deployment of Kenyan troops in Somalia.
At least 48 people have been killed after militants stormed into Mpeketoni and launched a major assault on a police station and hotels.
At least 26 people have been killed and several buildings burnt down in Mpeketoni after suspected al-Shabab gunmen opened fire.
Gunmen in Mombasa have shot dead an influential moderate Muslim preacher, who was an opponent of al-Shabab's preachings.
Militant group al-Shabab has claimed responsibility for an attack which the United Nations has called an "attack against the people".