Nairobi: Kenyan authorities offered $20,000 reward for information that may lead to the arrest of a terror suspect believed to be one of the masterminds of last year's attack on quarry workers in Mandera county. Police on Friday said the terror suspect, Mohamed Dubow, is believed to have led attack on quarry workers in Mandera county on July 7, 2015, where at least 14 people were killed and 12 others injured, Xinhua news agency reported. Police said Dubow, who is believed to have extensive terrorist network in northeastern Kenya, fled to neighbouring Somalia and police suspect he might have returned to the country. Police have also circulated Dubow's photos and appealed to the public to volunteer information that could lead to his arrest. The reward came after security officers offered $80,000 bounty on four terror suspects believed to be linked to the December 2014 killing of 36 quarry workers in the Mandera county.