A 71-year-old pensioner in Croatia threw a hand grenade at three electric company employees who had come to turn off his electricity because of outstanding payments.
In the incident in the small town of Pakrac, 120 kilometers east of Zagreb, a worker was critically injured on Wednesday, according to the Croatian media, citing the police.
The splinters of the exploded hand grenade wounded his head and stomach, it was said.
The two other E-Werk employees suffered fewer serious injuries.
The 71-year-old was arrested by the police at the scene.
Croatia had been at war with neighboring Serbia from 1991 to 1995 in the wake of the break-up of Yugoslavia.
Pakrac was on one of the front lines.
It is believed that numerous weapons from that period are still in circulation in the population, including rifles, pistols and hand grenades.