Northeastern Japan was jolted Sunday morning by a 7.0 magnitude aftershock, the largest to hit here in more than three months, triggering a tsunami warning for coastal areas trying to recover from the March 11 mega-disaster.

Initial reports indicated no damage as a result of this tremor, but residents — including workers at the stricken Fukushima Daiichi nuclear plant — were urged to evacuate. Tsunami waves between 10 and 20 centimeters high were reported in Miyagi and Iwate Prefecture.

The earthquake struck at 9:57 a.m., centered some 131 miles off the east coast of Sendai.

A tsunami warning indicated the possibility of waves as high as 50 centimeters. But at the Sendai airport, flights took off without disruption, television station NHK reported. Within an hour of the quake, work resumed at the Fukushima nuclear plant. None of the nuclear plants along Japan’s northeastern coast, including Daiichi, reported problems as a result of the tremor.

Japan has been bracing for major aftershocks since the 9.0-magnitude earthquake March 11 triggered a powerful tsunami, creating one of the largest disasters in this country’s history. The catastrophe left tens of thousands dead or missing, and scores more without homes or businesses. It also prompted the most serious nuclear crisis in a quarter century at the Fukushima plant, where three reactors sustained meltdowns.