Egyptian authorities held a memorial service Friday at the site of a hot air balloon crash in the southern city of Luxor last week that killed more than a dozen foreign tourists, including four Japanese, inviting embassy officials from the countries affected.

No relatives of the Japanese nationals killed in the crash attended the ceremony, according to a source in the Japanese Embassy in Cairo. Flags of the victims' countries were flown at the ceremony and a line of participants laid flowers.

"It is a very tragic accident," Kenji Enoshita, a counselor at the Japanese Embassy who took part in the service, told reporters. "Japan wants (the Egyptian authorities) to do their best to identify the cause of the accident and prevent it from happening again in the future."

An investigation panel established by the Egyptian government may release its findings as early as this week.

According to the Middle East News Agency, the 19 fatalities consisted of nine from Hong Kong, four from Japan, two each from France and Britain, one from Hungary and their Egyptian guide.

A British tourist survived the crash. The Egyptian pilot, who jumped from the balloon before it rose, exploded and plunged to Earth, remains in serious condition.