A number of taxi drivers have reported seeing ‘ghost passengers’ in Ishinomaki in Japan’s Miyagi Prefecture, an area that was devastated by the 2011 earthquake and tsunami.

Asahi Shimbun reports that Yuka Kudo, a senior at Tohoku Gakuin University majoring in sociology, interviewed more than 100 taxi drivers in Ishinomaki for her graduation thesis. Kudo asked the drivers whether they had any unusual experiences after the March 2011 disaster.

Related: Scientists solve 50-year-old mystery of Alaska tsunami

While many of the drivers ignored her or became angry, seven told the student about their strange experiences in the aftermath of the tsunami.

One driver, in his 50s, related a story about a woman who got into his cab near Ishinomaki Station. The woman told him to take her to the Minamihama district.  The driver then asked her “The area is almost empty. Is it OK?” The woman replied, in a shivering voice, “Have I died?”

Related: New Mexico police catch a 'ghost' on camera

When the driver looked back at his rear seat, no-one was there, according to the research.

Another driver, who was in his 40s, related how a man, apparently in his 20s, got into his cab and pointed toward the front. When the driver repeatedly asked the man for his destination, he replied “Hiyoriyama" (mountain). However, when the taxi arrived at the destination, the man had disappeared.

Related: The ‘Ghost Fleet of Mallows Bay’ in pictures

The seven drivers all started their meters for the “phantom journeys” according to the report. One driver showed Kudo his driver’s report, which noted an unpaid fare.

The magnitude 9.0 earthquake off the coast of Japan triggered massive tsunami waves, devastating parts of the country. More than 18,000 people lost their lives in the disaster.

Psychiatrists have identified “grief hallucinations” as a reaction to bereavement. A study published in 2007 by Agneta Grimby, a researcher at the University of Gothenburg in Sweden, surveyed 14 men and 36 women during the first year after the death of a spouse. Post-bereavement hallucinations or illusions were very frequent and even “considered helpful,” according to the research.