NAIROBI (AFP) - Two separate grenade attacks wounded at least eight people in northeastern Kenya, the latest in a series of blasts in the restive region bordering war-torn Somalia, police said Sunday.

"We had two incidents, eight people were wounded and taken to hospital," said regional police chief Leo Nyongesa.

Five people were wounded when a grenade was hurled late Saturday at a construction site at a school in the Ifo II section of Dadaab, the world's largest refugee camp hosting over almost 460,000 people.

Around the same time, attackers in the eastern town of Wajir threw a grenade into a restaurant, wounding three.

"No arrests have been made but an investigation is underway," Nyongesa added.

Kenyan police have repeatedly blamed Somalia's Al-Qaeda linked Shebab insurgents or its supporters for a string of similar attacks.

Last month the hardline Shebab warned Kenya of revenge attacks for sending tanks and troops into Somalia in October.

Kenya has been hit by a series of grenade attacks and explosions, mostly in Nairobi and in northern towns and camps housing Somali refugees close to the border.

Earlier this month attackers launched a deadly grenade attack on a restaurant in the port city of Mombasa.