Gunmen suspected to be armed robbers have killed 20 people in a village in the northwest Nigerian state of Zamfara, authorities said on Wednesday, Oct 31, a similar attack to one in June, Reuters reported.

Dozens of men armed with guns stormed Kaburu village early on Tuesday morning, demanding money before shooting and hacking people to death, local residents said.

"They were all shot to death while the village head was slaughtered with a sword," local government spokesman Salihu Anga said.

At least 27 people were killed in June when suspected armed robbers attacked several villages in Zamfara.

Islamist sect Boko Haram has killed hundreds across the north this year in its campaign for an Islamic state in a country split roughly equally between Christians and Muslims.