More than 100,000 packets of sliced bread have been recalled in Japan after parts of a rat's body were discovered inside two of them, the manufacturer said Wednesday.

Food recalls are rare in Japan, a country with famously high standards of sanitation.

Pasco Shikishima said it is investigating how the remains of the rodent had crept into its products.

The company said it is so far unaware of anyone falling sick after eating its processed white Chojuku bread, long a staple of Japanese breakfast tables.

Around 104,000 packs of the bread have been recalled.

"We would like to apologize deeply for causing trouble to our customers and clients," the company said in a statement on Tuesday.

On Wednesday, Pasco confirmed that the two packets of bread had been contaminated by parts of a black rat.

Pasco produces the bread at a factory in Tokyo, whose assembly line has been suspended pending a probe, it said.

"We will strengthen our quality management system to ensure there won't be a recurrence," it added.

Cleanness and hygiene are taken seriously in Japan, but food poisoning and recalls occasionally make Japanese headlines.

Last year, convenience store chain 7-Eleven apologized and announced recalls after a cockroach was found in a rice ball.

The latest health scare scandal in Japan involves a recall by drugmaker Kobayashi Pharmaceutical of dietary supplements meant to lower cholesterol.

The firm said last month it is probing five deaths potentially linked to the products, which contain red yeast rice.