A German tourist has died after collapsing following a lightning strike at Grand Canyon National Park.

Park rangers said emergency medical responders performed CPR on Thursday but couldn't revive the 64-year-old woman, who was part of a visiting tour group.

Authorities say five other people in the group were treated for minor injuries after lightning hit the ground nearby, but apparently didn't hit anyone.

The tour group was on the canyon's South Rim when the bolt of electricity struck at about 1:45 p.m.

Authorities have not released the woman's name.

Park rangers said it was unclear whether she suffered a heart attack.