Heavy winds Saturday knocked down several trees and power lines on the North Shore, causing a small number of residents to lose power, according to police and power officials.In Lynn, a power line fell in Chatham Street that police had to call National Grid crews to repair, said Lt. Stephen Haverek.Haverek said several tree branches also fell into streets, blocking roadways temporarily.In Salem a tree caught fire after it fell onto a power line on Cedarcrest Avenue, said Lt. Mary Butler.Butler said fire crews responded and extinguished the fire and National Grid crews were repairing the line.Butler said a telephone pole and at least one other power line were also damaged from heavy winds.At least 11 customers in Lynn and 12 in Salem were without power Saturday afternoon, according to National Grid spokesman David Graves.The National Weather Service also listed trees down on Russell, Birch and Nancy streets in Peabody.Amber Parcher can be reached at [email protected].