MOGADISHU (Reuters) - A suicide bomber rammed a car into a Somali military base about 30 km (20 miles) northwest of the capital, Mogadishu, on Friday, killing one soldier, the military said.

The attack, claimed by the militant group al Shabaab, occurred shortly before Friday prayers, when the base was almost empty, Major Abdullahi Ise told Reuters.

Three more soldiers were killed in a separate bombing targeting their truck as it headed into the capital with soldiers wounded in the first bombing, Ise said.

Al Qaeda-linked Al Shabaab carries out frequent bombings and other attacks in Mogadishu, in a campaign to topple Somalia’s Western-backed federal government. A car bombing in Mogadishu last Friday claimed by the group killed 45 people.

Also on Friday, al Shabaab spokesman Abdiasis Abu Musab told Reuters that militant forces had captured the town of Balad, 30 kilometers north of Mogadishu.

A military official confirmed that al Shabaab forces had ambushed the town. “We fiercely fought al Shabaab on the outskirts of the town and now they have entered the town,” Captain Nur Bile told Reuters.

Lieutenant Colonel Wilson Rono, a spokesman for the African Union-backed peace-keeping force AMISOM, said on Friday that there had been an ambush by al Shabaab but he did not have any details on casualties. He did not answer phone calls on Friday evening seeking further information.

The militants also want to drive out AMISOM, which helps defend the government. The 22,000-strong force began to withdraw troops in December and is scheduled to leave by 2020.

After a summit in the Ugandan capital Kampala, African nations that contribute troops to the peace-keeping mission said on Friday saying the schedule for withdrawing the troops was “not realistic”.

The drawdown by 2020 would “lead to a reversal of the gains made by AMISOM”, the statement read. It urged the United Nations Security Council to reconsider the drawdown.

Somalia has been in a state of chaos and lawlessness since the early 1990s, when dictator Mohammed Siad Barre was toppled by warlords.

President Mohamed Abdullahi has struggled to defeat the Islamist insurgency and restore security and stability, even though he has support from the peace-keepers, Western aid and frequent airstrikes on Islamist targets by the United States.