What you need to know:
- Mr Oloka has said the assault happened at around 5:30pm at Shimbir Fatuma, Mandera South.
Suspected Al-Shabaab militants have attacked workers at a quarry in Mandera County.
County Commissioner Kutswa Oloka has said the number of casualties is unknown.
"An incident has been reported but I can't tell if there are deaths or injuries since our security teams are headed there," he said on Thursday evening.
Mr Oloka has said the assault happened at around 5:30pm at Shimbir Fatuma, Mandera South.
The security teams comprise Kenya Defence Forces soldiers, Regular Police and police reservists.