(171014) -- MOGADISHU, Oct. 14, 2017 (Xinhua) -- Photo taken on Oct. 14, 2017 shows the explosion site near Safari hotel in Mogadishu, capital of Somalia. At least 40 people were killed and several others injured in a deadly bomb explosion near a popular hotel in Somali capital of Mogadishu on Saturday, the police said. (Xinhua/Faisal Isse)

Tens of thousands of people took to the streets in Somalia's capital, Mogadishu, on Wednesday to show their frustration with repeated attacks by Islamist terrorist group al-Shabaab, after a weekend truck bombing killed almost 300 people.

Protesters wore red bands around their arms and heads in support of the families of the victims of the most recent attack. Some carried placards addressed at al-Shabaab that read, "Stop killing innocent people."

"We are telling [al-Shabaab] that we are ready to take up arms and fight them from now on," a 16-year-old protester told dpa in Mogadishu.

Demonstrations against the extremists also took place in Somalia's volatile Puntland, Jubaland and Galmudug regions.

At least 281 people were killed and 300 others injured when a suicide bomber detonated a truck filled with explosives at a busy intersection in Mogadishu on Saturday. It was the deadliest single attack in the volatile East African nation's history.

Before detonating the truck he was driving, the suicide bomber had raced along a Mogadishu street at high speed, rolling over motorcycles and cars and shunting vehicles stuck in traffic.

Somali President Mohamed Abdullahi Mohamed called the attack a national tragedy.

Police said Wednesday it made several arrests in relation with the bombing but did not provide further details.

No group has claimed responsibility for the attack but many suspect al-Shabaab, a militant group affiliated with the al-Qaeda terrorist network, which is seeking an Islamist state in Somalia.

A 22,000-strong African Union force supports the Somali military in its fight against the terrorists.