Kenyan police say a grenade attack at a church in the capital, Nairobi, killed a nine-year-old boy and wounded three other children on Sunday.

Police chief Moses Ombati says he believes the attack is tied to sympathizers of al-Shabab militants in Somalia.

On Friday, Kenyan forces battling al-Shabab in Somalia pushed into Port Kismayo, forcing the Islamist militants to retreat from the largest remaining stronghold.

Police say the children in Kenya were at a Sunday school service at Saint Polycarp Church in Nairobi when someone hurled a grenade into the building.

“We were just worshipping God in church when we suddenly heard an explosion and people started running for their lives but unfortunately we came to realize that the explosion had injured some kids who were taken to hospital and unfortunately one succumbed,'' said worshipper Irene Wambui.

There has been no claim of responsibility for the attack.

Kenya has seen a series of similar attacks on churches since it sent troops into Somalia last year.

In July, gunmen threw grenades and opened fire inside two churches in the eastern town of Garissa, killing 17 people.

President Raila Odinga suggested the attacks were meant to spark tensions between Muslims and Christians. And he said the violence stemmed from terrorism, not religious conflict.

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