Al-Shabab has vowed to carry out more attacks in Mogadishu following a truck bomb blast that killed scores of people in the Somali capital.

The warning came after the armed anti-government group claimed responsibility for Tuesday's blast outside a government compound in Mogadishu, which killed at least 70 people and left many others wounded, in one of the country's deadliest ever suicide attacks, officials and witnesses said.

Al Jazeera's Peter Greste reports from Nairobi, Kenya.