At least 30 people have been killed in north-west Nigeria byunknown gunmen, Radio Nigeria and other media reported Sunday.The gunmen stormed Yar Galadima village in Zamfara state, where a local vigilante group and community leaders were holding a meeting on how to protect the area from cattle rustlers and robbers on Saturday.The gunmen arrived suddenly on motorbikes and fired at everyone on sight, one of the survivors told Radio Nigeria.A large number of people were reported injured.The news of the attack came as Nigerians were still waiting for official confirmation of an attack Saturday on a mosque in Buni Gari village in north-eastern Yobe state, in which 20 people were reportedly killed by unknown assailants.