MOSCOW, Jan 5 (Reuters) - Eight police and national guard troops have been killed and 317 were injured during unrest in several regions of Kazakhstan, Sputnik news agency reported on Wednesday, quoting the interior ministry. Earlier Kazakhstan"s President Kassym-Jomart Tokayev said he had taken over as head of the country"s Security Council and promised to act with "maximum toughness" amid the worst unrest for more than a decade in the Central Asian republic.