BRASILIA, March 2 (Xinhua) -- Brazil has registered 28 lightning-related deaths so far this year, an increase of 64 percent from the same period last year, Brazil's National Institute of Spatial Researches said Sunday.

    The institute attributed the rise in the number of deaths caused by lightning to the La Nina phenomenon, the cooling of the waters in the Pacific Ocean that alters the circulation of winds and leads to the formation of tempest.

    Human activities like pollution, construction and asphalt that create "isles of heat" also contribute to the rise of lightning-related incidents, according to Osmar Pinto Junior, a coordinator with the institute.

    During last week alone, seven people died of lightning incidents in Brazil.