No fewer than 36 workers in the quarry have been attacked by gunmen in Kenya’s Mandera country, which shares border with Somalia.
The County governor who disclosed this on Tuesday said they drew a parallel with another recent raid by al Shabaab militants.
Earlier, 28 people were killed in the area last month when al Shabaab militants hijacked a Nairobi-bound bus, causing widespread anger.
Kenya has suffered a string of gun and grenade attacks since it sent troops into Somalia to fight al Shabaab in late 2011.
According to an eyewitness the workers were attacked while sleeping in their tents at the quarry.