A vehicle laden with explosives ploughed into a guest house hosting government officials in Bardera, 450 kilometers west of the capital Mogadishu, area police commander Hussein Adan, said.
"The explosion destroyed most parts of the building and five security guards died in the blast," Adan said.
Eleven people, including the governor Ahmed Bulle Gared, were injured, he added.
There was no immediate claim of responsibility for the attack, but Islamist group Al-Shabab remains a potent force in the troubled Horn of Africa nation despite multinational efforts to degrade its leadership.
Mohamud Saney, who witnessed Tuesday's attack, said, they had "never heard anything as big as the explosion."
"It shook the earth like and earthquake."
Al-Shabab has been waging a bloody insurgency against the central government in the fragile nation for about 15 years.
The UN last month said that 2022 was the deadliest year for civilians in Somalia since 2017, largely because of an increase in mass-casualty attacks by the jihadist group.
Although forced out of Mogadishu and other main urban centers more than a decade ago, Al-Shabab remains entrenched in parts of rural central and southern Somalia.
Somali Suicide Attack Wounds Governor
MOGADISHU - At least five people were killed and 11 others, including a regional governor, wounded in a suicide attack on Tuesday in southern Somalia, a police commander told AFP.
