BAUCHI, Nigeria (Reuters) - At least 20 people were killed in Nigeria's Sokoto state when gunmen attacked a market and torched cars, as armed gangs continue to wreak havoc in the northwest part of the country, a state official and local member of parliament said on Saturday.

       Northwestern Nigeria has since last December witnessed a wave of kidnappings of school children and villagers for ransoms by bandits, disrupting everyday life for millions of citizens.

       Idriss Gobir, special advisor to the Sokoto police affairs minister, said the armed bandits rode on motorcycles and shot sporadically, killing several people.

       "The bandits in large numbers killed at least 20 people that we have seen and counted and set nine vehicles on fire," he told Reuters by telephone.

       Hussain Boza, a local member of parliament in Sokoto, blamed the attack on a lack of adequate security in the state.

       A Sokoto police spokesperson confirmed the attack but could not immediately say how many people had been killed.

       Parts of Sokoto, like other neighbouring states in the northwestern part of the country, are under a telecommunications blockade as part of a security operation to disrupt the operations of the armed gangs.

       On Thursday, security agents rescued 187 people who had been abducted by armed gangs in Zamfara state.

       (Reporting by Ardo Hazzad; Writing by MacDonald Dzirutwe; Editing by Paul Simao)