A French lawyer and arms collector was killed on Friday when he pulled the pin out of a hand grenade he had received from a friend in the post, police said.

"The blast was accidental and killed one person," police said after the explosion at lawyer Jerome Muriaux's offices in the chic eighth arrondissement or district of Paris.

Muriaux, 45, "ordered grenades, doubtless from a friend, and received them in the post," a police source said.

"He opened the package, took out a grenade and pulled the pin, thinking it inert," the source said, asking not to be named.

Several people were lightly hurt in the explosion, police said.

"I suddenly heard a blast. There was smoke, shattered glass. My colleague saw that the victim had his arm cut off," said Charly Husson, who works in an office that shares the same courtyard as the lawyer's.

Dozens of police and emergency workers arrived shortly after the blast.