TOKYO, Apr 4 (AP/UNB) - A powerful storm lashed Japan with heavy rain and strong winds, killing four people and paralyzing air and train traffic in Tokyo, officials said Wednesday.

The spring storm swept across Japan's main island of Honshu on Tuesday, with winds of more than 144 kilometers (89 miles) per hour - typhoon strength. The Meteorological Agency said the storm had left the region by Wednesday, but it urged caution as strong winds would persist in parts of northern Japan.

Two people were killed in separate warehouse collapses in Toyama in the north and Kagawa in the south on Tuesday. Police reported two more deaths overnight - an elderly man who fell off a roof in Iwate and a woman crushed to death by a fallen tree in nearby Miyagi.

Officials said hundreds more were injured across the country.

The storm had brought commuter train service to a halt and grounded more than 500 flights in and around Tokyo. Train service returned to normal Wednesday but about 70 more flights were canceled.

Cooling of a spent fuel storage pool each at two separate nuclear power plants in northern Japan temporarily stopped when pumps stopped due to power failure, but resumed in about 30 minutes without affecting safety, their operator Tohoku Electric Power Co. said.

The Fukushima Dai-ichi nuclear power plant that suffered meltdowns at three reactors after last year's tsunami was unaffected by the storm.