MINNEAPOLIS -- The National Weather Service says severe storms over the weekend spawned four tornadoes in east-central Minnesota and western Wisconsin.

Two occurred early Saturday morning north of the Twin Cities, and two occurred Saturday night to the east of the metro. There were no reports of injuries.

Weather Service survey teams assessed the damage on Sunday and determined the path and strength of the Saturday tornadoes. Here are their findings:

Northwest Isanti County: An EF-1 tornado with estimated peak winds of 90 mph was on the ground for about 5 minutes, starting just before 1 a.m. It traveled three miles with a maximum width of 100 yards. The Weather Service said the tornado damage was embedded amid damage from strong straight-line winds.

Northern Chisago County: An EF-0 tornado with estimated maximum winds of 80 mph tracked from the west shore to the south shore of Rush Lake, between Braham and Rush City. It touched down at about 1:24 a.m. and was on the ground for just three minutes, traveling 1 1/2 miles with a maximum width of 100 yards. The tornado damaged boats and docks on the lake.

Southern Washington County: While survey crews could not locate damage to determine an exact path, radar confirmed a "debris signature" — indicating a tornado touchdown — west of Afton from about 9:42 p.m. to 9:51 p.m. The tornado was estimated to be an EF-0 with maximum winds of 65 mph.

Southern Washington County into Pierce County: An EF-1 tornado with estimated peak winds of 100 mph was on the ground for about a half-hour, starting at 9:53 p.m. about 5 miles north of Hastings, Minn. It tracked across the St. Croix River and into Pierce County, Wis., covering about 9 1/2 miles with a maximum width of 400 yards. Survey teams found "extensive tree damage," with many snapped off halfway up the trunk. Some farm outbuildings also were damaged. The Weather Service reported that the worst damage was found atop the bluffs on the Wisconsin side of the river.