Irish police are seeking information related to a Japanese couple in their 60s who have been missing in the western part of the country since last Saturday.

The police said a 63-year-old man and a 61-year-old woman who traveled from Japan have not been seen since they checked out of a hotel on the morning of that day.

The car they rented was found at a seaside parking lot in the resort town of Kilkee. The car was apparently parked there around 9 p.m. the same day, according to Japanese media reports. The weather was bad on that day.

The couple, named Eiji Takagi and Ushio Azaki, according to media reports, were supposed to take a flight to Tokyo via London on Monday, but did not show up. The Japanese Embassy in Ireland said the man, who had U.S. citizenship, and the woman arrived in Ireland around Aug. 18 from Japan.

The Irish Times reported Thursday that the location of a pair of rucksacks could prove key in determining what happened.