MAIDUGURI, Nigeria, Sept 8 (Reuters) - Gunmen kidnapped 20 people in remote Sokoto State in northwest Nigeria, police said on Wednesday, in what a local government source described as a spillover from a crisis in neighbouring Zamfara State where a military crackdown is underway. Gangs of ransom seekers have been kidnapping children from their schools, villagers from their homes and travellers from their vehicles across northwest Nigeria since last December and authorities have been struggling to respond. Sanusi Abubakar, a police spokesman in Sokoto State, said gunmen had seized 20 people during an attack in the rural Dange-Shuni area. The kidnappers also seized livestock and food supplies, according to a source within the state government who did not wish to be named. The source said Sokoto was seeing an influx of bandits who were arriving from Zamfara, where a blackout on telephone and internet networks has been imposed while security services conduct a crackdown on gangs camped out in the state. read more Little information has filtered out of Zamfara State since mobile networks were shut down at the weekend by order of the national telecoms regulator. Military spokespersons in the federal capital Abuja did not respond to multiple requests for comment on Wednesday on what exactly was happening in Zamfara. Kidnappings have become so routine across northwest Nigeria that most no longer make headlines. In the latest major incident in Zamfara, at least 73 pupils were abducted from their secondary school in the village of Kaya last week. read more The kidnap crisis has affected every aspect of life in the northwest. Large numbers of children have dropped out of school, food is often hard to come by because farmers cannot reach their lands, and families are being kept apart because people are afraid to travel by road.