Update, 3:50 p.m. Monday: A major earthquake in the Pacific Ocean off of northeastern Japan triggered tsunamis throughout a coastal region that includes the nuclear plant that suffered a meltdown after the devastating temblor of March 2011.
The quake, measured at magnitude 7.4 by the Japan Meteorological Agency and 6.9 by the U.S. Geological Survey, struck at 5:59 a.m. Tuesday Japan Standard Time, or 12:59 p.m. Monday PST.
The Japan Meteorological Agency has reported tsunami waves as high as 1.4 meters -- about 4 feet -- so far. The agency warned that surges as high as 3 meters -- about 10 feet -- were possible.
Residents of coastal areas were urged to leave for higher ground immediately and not return until an all-clear was sounded. So far, only minor injuries have been reported in the quake zone.
Japanese TV network NHK is offering an English-language version of its live coverage -- above -- featuring simultaneous translation.
One of the earliest reports the network aired said that pumps in the cooling system at the Fukushima Daini nuclear power plant shut down after today's quake. Fukushima Daini is about 6 miles from the Fukushima Daiichi nuke that suffered core meltdowns after the 2011 earthquake and tsunami.
Officials with the Tokyo Electric Power Co., which owns both plants, said that there was no immediate danger that fuel rods at Daini would overheat. The utility later said the cooling-system pumps were restarted about 90 minutes after the earthquake struck.
The power company said the quake caused no new damage at Fukushima Daiichi, a heavily contaminated site that is in the process of being decommissioned.
About 16,000 people died in 2011's 9.1-magnitude offshore quake, and another 2,500 are still listed as missing. Most of those killed perished from tsunami waves 100 feet or more over normal sea level.
The 2011 earthquake unleashed tsunami waves all along the U.S. West Coast, causing serious damage at several California locations, including Crescent City and Santa Cruz.
The federal Pacific Tsunami Warning Center says there is no tsunami danger to the West Coast from today's quake.
Here's the latest from The Associated Press:
TOKYO — A powerful earthquake off the northeast Japanese shore Tuesday sent residents fleeing to higher ground and prompted worries about the Fukushima nuclear power plant destroyed by a tsunami five year ago.
Lines of cars were seen snaking away from the coast in the predawn hours after authorities issued a tsunami warning and urged residents to seek higher ground immediately. The warning was lifted nearly four hours later.
The magnitude 7.4 earthquake struck in the same region that was devastated by a tsunami in 2011, killing some 18,000 people.
There were reports of minor injuries and damage, Japanese broadcaster NHK said. The earthquake shook buildings in Tokyo, 240 kilometers (150 miles) southwest of the epicenter.
NHK also showed one person's video of water rushing up a river or canal, but well within the height of the embankment. It was eerily reminiscent of the 2011 disaster, when much larger tsunamis rushed up rivers and overflowed, wiping away entire neighborhoods.
On Tuesday, tsunami waves were recorded along the coast. The highest one was 1.4 meters (4.6 feet) in Sendai Bay. A tsunami advisory for waves of up to 1 meter (3 feet) remained in effect along the coast.
The operator of the Fukushima Dai-ichi plant said there were no abnormalities observed at the plant, though a swelling of the tide of up to 1 meter was detected offshore.
The plant was swamped by the 2011 tsunami, sending three reactors into meltdown and leaking radiation into the surrounding area. The plant is being decommissioned but the situation remains serious as the utility figures out how to remove still-radioactive fuel rods and debris and what to do with the melted reactor cores.
Plant operator TEPCO said a pump that supplies cooling water to a spent fuel pool at the nearby Fukushima Dai-ni plant stopped working, but that a backup pump had been launched to restore cooling water to the pool. Both plants are run by Tokyo-based TEPCO.
Naohiro Masuda, head of TEPCO's decommissioning unit, said he believes that the pump was shut off automatically by a safety system as the water in the pool shook.
He said decommissioning work at the destroyed Dai-ichi plant had been temporarily suspended because of the earthquake.
The U.S. Geological Survey measured the magnitude at 6.9.