The United Nations believes that a Palestinian Engineer, who lived in Gaza and worked as a senior engineer at the Gaza Power Plant, and went missing in Ukraine more than three weeks ago, is being held at an Israeli detention facility, American NPR reported.The Engineer, Dirar Abu Sisi, 42 years old, went missing on Feb 19 after he boarded a train in Kharkiv heading to the capital, Kiev. Spokesperson of the Interior Ministry in Ukraine, Viktoria Kushnir, said Abu Sisi was living in Ukraine where he applied for citizenship.

The Authorities in Ukraine opened an investigation into the incident, but no have been no reports of progress.

Abu Sisi reportedly boarded the train from Kharkov city, east of Ukraine, and was heading to Kiev (480 kilometers away) to meet his brother who flew from Holland to visit him. The two have not seen each other for 15 years.

Fathi Hammad, Interior Minister of the Hamas-led government in Gaza, sent a letter to his Ukrainian counterpart, Anatoly Mogilev, demanding that he act immediately in order to reveal the circumstances that led to the abduction of Abu Sisi, and to ensure his release.

NPR reported that spokesperson for the United Nations High Commissioner, Maskim Butkevych, stated that Abu Susi is held by the State of Israel, and that he was transported there shortly after his abduction.

The UN believes that Abu Sisi was likely abducted by Israeli agents with the help of Ukrainian associates.

Veronika, the 32-year-old wife of the Engineer, said that the Israeli Mossad is behind the kidnapping that was carried out “to sabotage Gaza’s power plant where he worked as a senior engineer”.

She told the Associated Press that Abu Sisi was the main engineer at the station that was repeatedly targeted and bombarded by Israel.

She told the agency that her husband’s lawyer stated that Abu Sisi was kidnapped and was moved to Israel.

The Associated Press tried to talk to the lawyer but he declined comment, citing a gag order.

Veronika said that the family decided to move back to Ukraine due to instability and lack of safety in Gaza, and that she and her husband took their three sons and three daughters to Ukraine to apply for citizenship.

After submitting all the family’s applications, Abu Sisi was informed that he needs to report to a government agency that was processing his case in Kharkiv. When he visited the agency, he was briefly detained and the authorities told him it was a routine procedure.

On the night of February 18th, Abu Sisi boarded an overnight train to Kiev and has been missing since then.

Israeli human rights group, Hamoked, active in defending Palestinian human rights, said that Abu Sisi has been held at the Shikma detention center, near Ashkelon since February 19.

Israel had no comment on the abduction, while the Israeli Prison Service said it had no information regarding the issue.

The Israeli Shin Bet (Israel’s International Security Service), also made no comment, and only stated that a gag order is in place.