Yvan Colonna, a jailed Corsican nationalist who was attacked at a prison in Southern France, died on Monday, according to French daily Le Parisien.

The strangling of Colonna by a fellow inmate three weeks ago, which left him in a coma, prompted violent protests in Corsica in recent weeks, including clashes with police, and calls for nationalist prisoners to be transferred from the French mainland to the island, closer to their families.

Colonna was serving a life sentence for...