Japan's daily number of confirmed coronavirus cases on Wednesday topped 1,300, remaining at high levels ahead of next week's summer holiday peak, with health authorities calling on people to be cautious when they travel to their hometowns and elsewhere.

Tokyo reported 263 new cases of the novel coronavirus, amid the continued resurgence of infections in August. Average daily new infections over the week through Wednesday stood at 346.3, according to the metropolitan government.

People wearing face masks due to the novel coronavirus pandemic walk in Tokyo's Shibuya district with parasols amid scorching summer heat on Aug. 5, 2020. (Kyodo)

The single-day figure, down from Tuesday's 309, brought Tokyo's cumulative total to 14,285. The capital, which has a population of nearly 14 million and has the highest number of infections in the country, saw a record of 472 reported Saturday.

The city government has raised its alert for the pandemic to the highest of four levels, meaning "infections are spreading," requesting that karaoke venues and establishments serving alcohol close by 10 p.m. through the end of August.

It said the number of patients in serious condition due to the virus stood at 21, down one from Tuesday.

The daily figures reflect the most recent totals reported by health authorities and medical institutions.

With Japan's Bon holiday season beginning next week, there are concerns that the movement of people will further spread the virus.

Shigeru Omi, chairman of a government advisory panel on the COVID-19 respiratory illness caused by the virus, urged people in Japan to take sufficient measures against infections and, if possible, exercise self-restraint in returning their hometowns.

"We particularly hope people will avoid dining together in large numbers," Omi said at a press conference, with the committee's proposal reiterating the importance of staying away from the 3Cs -- confined spaces, crowded places and close-contact settings.

Some prefectural governors voiced their concerns over potential visits of people from urban areas, where high numbers of infections have been reported, during the upcoming holiday season.

"Please think again if (your family visits) really have to be now," Shizuoka Gov. Heita Kawakatsu said.

The government of the central Japan prefecture asked residents to avoid traveling to Aichi and Osaka prefectures, in addition to Tokyo, while raising its alert level for trips to four prefectures -- Gifu, Kumamoto, Miyazaki, and Okinawa -- saying they should only be done "with special caution."

Yasutoshi Nishimura, minister in charge of the coronavirus response, called on the public to consider what local governments are saying before making decisions about Bon holiday trips.

But he said the government will not officially ask for people to exercise self-restraint.

The resurgence of infections has been observed in many other parts of Japan.

Aichi Gov. Hideaki Omura told a press conference on Wednesday that the prefectural government will declare a state of emergency, calling on residents to refrain from making nonessential outings and trips beyond prefectural borders.

Aichi Gov. Hideaki Omura holds a press conference in Nagoya, central Japan, on Aug. 5, 2020, announcing the declaration of a COVID-19 state of emergency by the prefectural government, effective from the following day through Aug. 24. The governor requested residents to refrain from making nonessential outings and trips beyond prefectural borders. (Kyodo)

The state of emergency will be effective from Thursday through Aug. 24.

The central Japan prefecture centering on Nagoya, one of the three largest metropolitan areas in the country along with Tokyo and Osaka, confirmed on Wednesday 147 new cases, bringing its cumulative total to 2,531.

In Osaka Prefecture, western Japan, 196 new cases were confirmed, with around 200 cases constantly being reported daily in recent days.

The Osaka prefectural government will begin asking nightlife establishments in the major entertainment district of Minami to suspend or shorten their hours of operations from Thursday.

Tokyo Gov. Yuriko Koike has also said she would declare a state of emergency in the capital if necessary.