Japan will discontinue quarantine inspections aimed at detecting cases of A/H1N1 influenza aboard flights arriving in Japan from North America as early as the end of this week, health authorities said on Tuesday.

The government made the decision at a time when the number of domestic infections cases of A/H1N1 flu in Japan rose above 170 Tuesday.

At a press conference, Chief Cabinet Secretary Takeo Kawamura said that though the quarantine measure aboard flights has been productive and helped detect the first four infection cases at the Narita International Airport, the government needs to shift its focus to domestic measures in line with the trend of the flu's transmission.

"From this aspect, we think we need to scale down the operations to prevent entry of the new flu," said Kawamura, adding that the government has yet to decide on the timing of the termination.

At a separate press conference, Health, Labor and Welfare Minister Yoichi Masuzoe said that the virus is already spreading domestically.

In light of the latest development of the flu's transmission, Masuzoe said that the government needs to devote human resources to stop the rapid domestic spread of the new flu.

The health minister indicated that local governments may take more measures to tackle the spread of the new influenza, including hospitalizing patients and restricting people's movements or activities in particular.

Latest statistics show that the confirmed cases of A/H1N1 influenza in Japan has risen to 178 Tuesday after local governments in Hyogo and Osaka prefectures reported 15 confirmed cases, including a 1-year-old girl.