The macabre images released by the Guardia Civil look like something out of a gory, zombie-apocalypse film.
The Guardia Civil was alerted by a farmer from Sorogain, Navarra, that an electrical storm which lashed down on the area on Saturday night, had left a ghastly aftermath.
It had resulted in the death of 28 sheep and one ram on his property.
Several other sheep and a cow owned by a neighbouring farmer also died as a result of the electrical storm after being struck by lightning.
Death by lightning is rare but not unusual.
In August 2016, lightning killed 323 reindeer in a private hunting reserve in central southern Norway, in a natural massacre that counts as the deadliest lightning strike on record.
Guinness World Records says the 'worst lightning strike disaster' occurred in 1971, when a bolt took down a commercial airplane in Peru, killing 91 people.
Guinness reports that the largest recorded number of livestock killed by a single lightning bolt is 68.
The incident took place in New South Wales, Australia, on October 31, 2005. A further three jersey cows were paralyzed for a few hours, but later recovered.
There is also a recording of 52 geese in Canada in 1932 to have died from a lightning bolt.
An estimated 24,000 people die each year from lightning, of which Spain sees an average of 10-15 people.
The riskiest activities include fishing, boating, camping, and golf.
Comment: In addition, a strike killed 2 horses in Kent, UK on August 13.