By Abdisalan Mohamed

GARISSA, Kenya (Reuters) - A suspected grenade attack on a church in the eastern Kenya town of Garissa injured at least 11 people on Sunday, the Kenya Red Cross and local media said.

Militants have staged several attacks since Kenya sent troops into Somalia a year ago to fight al Qaeda-linked al Shabaab rebels following raids and kidnappings in the border region that threatened tourism and wider regional instability.

Of the 11 injured people at Garissa's district hospital, three were in need of air evacuation and the hospital urgently needed blood, the Kenya Red Cross said.

Mohamed Musa, superintendent of the hospital, told Reuters there had been no deaths reported.

Two television channels said the Utawala Interdenominational Church, in a police compound, had been attacked and that gunfire could still be heard at the scene of the blast. No one from the police was immediately available to comment.

In September, a grenade attack on a church in Nairobi by suspected al Shabaab sympathizers killed a nine-year-old boy. In July, attacks on two churches in Garissa killed 17.

(Additional reporting by George Obulutsa in Nairobi; Editing by Louise Ireland)