Al Shabaab have threatened attacks in east Africa and the United States

MOGADISHU (REUTERS) - Somali Islamist militants have threatened attacks in east Africa and the United States, warning President Barack Obama he would hear "shocking news" as punishment for a US missile strike that killed the rebel group's leader last week.

Al Shabaab made the threats late on Monday, hours after launching twin attacks inside Somalia against African peacekeepers and a government convoy. The death toll from those bombings rose to at least 18 on Tuesday, police said.

"Let our mujahideen (fighters) wait for good news. And let Obama wait for shocking news," senior al Shabaab official, Fuad Mohamed Khalaf Shongole, said in a recorded message, promising to avenge the death of Ahmed Godane in a US raid on Sept. 1.

Al Shabaab demonstrated its ability to strike abroad on Sept. 21, 2013, when the group launched an attack on the upscale Westgate shopping mall in Nairobi, Kenya, that killed 67 people.