A police officer stands guard near the Brussels airport in Zaventem, Belgium, March 24, 2016, two days after terror attacks in the Belgian capital. Patrik Stollarz/AFP/Getty Images

Two New Yorkers, siblings Alexander and Sascha Pinczowski, were confirmed Friday as having been killed in Tuesday's terror bombings at the Brussels airport, the New York Daily News reported.

The brother and sister, Dutch citizens, had come to Brussels via the Netherlands, where they visited family, New York City's WCBS-TV reported. They were on a phone call with relatives when the blast detonated and their line went dead. Other news outlets, including Dutch newspaper Algemeen Dagblad, reported their father is from Maastricht, a town in the Netherlands.

"The Belgian authorities tonight provided, to the families gathered at Astrid Hospital in Brussels, a list of the names of all remaining victims of the tragedy of March 22 who remain alive. Sadly, our beloved Alexander and Sascha were not among them," Jim Cain, a former U.S. ambassador to Denmark whose daughter Cameron was engaged to Alexander, said in a statement. "We are grateful to have closure on this tragic situation and are thankful for the thoughts and prayers from all. The family is in the process of making arrangements.

“It’s agonizing beyond any parent’s worst nightmare,” Cain told the Daily News by phone from Belgium. “They had no other children,” Cain said of parents Edmond and Marjan. “They are strong Dutch fiber, but you can only imagine how devastating this is for them – for all their friends and family.

“Then this morning authorities and the ambassador came to visit the family and confirmed that overnight the remains of Sascha and Alexander had been positively identified,” he said.

He said the only comfort was “knowing that Alex and Sascha are together.”

Earlier, Cameron Cain had appealed for help finding the Pinczowskis:

U.S. officials confirmed Friday that two Americans were among the 31 killed in the attacks on the city's airport and subway system but did not reveal their names.

It’s not clear if officials were referring to the Pinczowski siblings, who listed New York City as their hometown on Facebook, or a married couple from the South still counted as missing early Friday.

Justin Shults, a Tennessee native, and his wife, Stephanie, originally from Kentucky, dropped Stephanie's mother off at the airport just before the explosions. They have not been heard from since.

Sacha Pinczowski, 26, graduated from Marymount Manhattan College last year and returned to Europe a few months ago when her student visa ran out, but planned to move back to New York. Alexander, 29, was returning to New York's John F. Kennedy International Airport on Tuesday to meet up with Cameron Cain and then travel to North Carolina for a wedding and to celebrate her birthday, her father said.

Speaking after meeting with Belgian Prime Minister Charles Michel in Brussels, U.S. Secretary of State John Kerry said the "United States is praying and grieving with you for the loved ones of those cruelly taken from us, including Americans, and for the many who were injured in these despicable attacks."