New Delhi: An alert has been sounded in 10 districts of Gujarat as Cyclone Vayu has turned "very severe" and its impact is expected to remain strong for 24 hours even after its landfall Thursday, officials said.

As many as 52 teams of the National Disaster Management Relief Force (NDRF), comprising around 45 rescuers each, have been moved to the state, while 10 columns of the Indian Army have been kept on stand-by.