Nineteen people have been killed in twin car bombings in central Somalia claimed by Al-Shabaab, a local militia commander in the Hiran region said.
Two cars packed with explosives were simultaneously detonated in Mahas, a town in Hiran where a major offensive was launched last year against the Al-Qaeda-linked militant group.
The attack was claimed by Al-Shabaab, which has been waging a years-long insurgency against the fragile central government, according to the SITE monitoring group.
"Nineteen people, including members of the security forces and civilians, died in the blasts," said Mohamed Moalim Adan, a leader of a community militia allied with the government in Mahas.
Abdikarim Hassan, a traditional elder in Mahas, said "nearly 20 people died in the blasts" and most were civilians.
Another community leader, Mohamud Suleyman, said 52 people were wounded and "most were transported to Mogadishu for treatment."
Security officials and local leaders said two military bases were targeted in Mahas in retaliation for operations against the militants.
Al-Shabaab claimed responsibility in a statement issued by its media unit, saying fighters had detonated explosives at military bases in Mahas and also attacked another base in Dadan 'Ad, about 17 kilometres (10 miles) away, according to SITE.
"The terrorists, after having (been) defeated, resorted to desperately targeting civilians, but this will not stop the will of the people to continue defeating them," said Osman Nur, a police commander in Mahas.
Somalia's President Hassan Sheikh Mohamud has declared "all-out war" against Al-Shabaab, which has been waging a bloody insurgency against the frail internationally-backed federal government for 15 years.
In July, local clan militias known as "Macawisley" launched a revolt against Al-Shabaab in parts of central Somalia, and Mohamud sent in troops in September to support the fight-back.
In recent months, the army and the militias have retaken swathes of territory in the central states of Galmudug and Hirshabelle (where Hiran is located) in an operation backed by US air strikes and an African Union (AU) force known as ATMIS.
But the insurgents have frequently retaliated with bloody attacks, underlining their ability to strike at the heart of Somali towns and military installations despite the offensive.
Although forced out of the country's main urban centres around 10 years ago, Al-Shabaab remains entrenched in vast swathes of rural central and southern Somalia.
On October 29, 121 people in the capital Mogadishu were killed in two car bomb explosions at the education ministry, in the deadliest attack in the troubled Horn of Africa nation in five years.
Eight civilians died on November 27 in a 21-hour siege at a hotel in Mogadishu popular with politicians and government officials.
A triple bombing in October in the city of Beledweyne, the capital of Hiran, left 30 people dead including local officials.
And at least 21 people were killed in a siege of a Mogadishu hotel in August that lasted 30 hours before security forces were able to overpower the militants inside.
