The Asahi Shimbun said Friday it had received death threats against its staff, the latest in a string of threats against journalists.

The left-leaning newspaper, which heavily criticized former Prime Minister Junichiro Koizumi for visiting Yasukuni Shrine, received two postcards warning that several of the newspaper's workers would be killed, according to an Asahi official who spoke on customary condition of anonymity.

"It is inevitable that one or two of your staff will be killed," the official quoted one of the two handwritten threats as saying.

The postcards were mailed earlier this month and were signed with the same name, he said.

The threats alluded to a 1987 shooting in which a rightwinger entered the Asahi's bureau in Nishinomiya, Hyogo Prefecture, and killed one journalist and wounded another, saying a similar attack could happen again, the official said.

The paper has tightened security at all of its bureaus and handed the postcards over to police, according to the official.

Friday's case is the latest in a new string of threats against journalists, academics and lawmakers, some appearing to come from a resurgent nationalist fringe.

The Yomiuri Shimbun, the country's biggest newspaper, said Thursday it received a mystery parcel containing a gun, bullets, a small amount of amphetamines and a slice of melon. It was unclear what the meaning of the package was.

In August, a member of an extremist nationalist group burned down the home of lawmaker Koichi Kato after he slammed Koizumi for going to Yasukuni Shrine.

The Asahi also ran an editorial critical of Koizumi's pilgrimage.