I thought OTC is the area around Jack and Jill, only news of one grenade.
I seriously doubt whether Al shabaab are involved. There are several such attacks that have happened around Nairobi , carried out with the same Grenades. Problem though is that our police force is well suited for beating up old women during riots, and have never closed any of the investigations
The police are yet to close investigations, especially on the Uhuru Park attacks which bear closest semblance to what we have today.
Our police force is a big let down to the country. Reforms cant go through as the same police will halt pro reform campaigns and be at the beck and call of anti-reform politicians.
Back to the grenade attacks, looks like some guys with a sinister motive and a grenade stock pile are on a mission. The attack on Al shabaab is just a motive in whatever they are up to. The "no" rally was another one.