The return rush from the New Year's holidays continued to peak Saturday as people coming back from hometowns or vacation spots swamped airports, highways and train stations nationwide.

The planes arriving at Tokyo's Haneda airport were almost full, whether they were domestic or international flights.

Traffic jams as long as 23 km were seen at the Toyokawa interchange on the Tomei Expressway and the Kusatsu junction on the Meishin Expressway, according to the Japan Road Traffic Information Center.

Some of the Tokaido shinkansen bound for Tokyo were overfilled to 160 percent of capacity after the reserved seats sold out, Central Japan Railway Co. (JR Tokai) said. Other bullet trains nationwide were similarly packed.

The Tokaido and Sanyo shinkansen lines were back on schedule a day after a fire along the tracks in central Tokyo delayed service for about five hours.

The incident caused many passengers to miss connections, leading JR Tokai and West Japan Railway Co. to let those stranded at major stations use empty trains as temporary hotels. At Tokyo Station, 2,187 passengers spent Friday night in such trains, as did dozens at Nagoya, Shin-Osaka and Hakata stations.

"I'm relieved I was able to change our reserved seats (without extra fees)," Mitsue Okamura, a 43-year-old homemaker from Suita, Osaka Prefecture, said Saturday at Tokyo Station. The delay will cause her family to get home a day late, she said.

The Tokyo Metropolitan Police and the Tokyo Fire Department were still investigating the cause of the blaze, which began early Friday morning near JR Yurakucho Station.

Police suspect the fire started through a short circuit under a water tank placed between a video game arcade and a pachinko parlor, and then spread to adjacent buildings.