An elderly Holocaust educator Hamas terrorists are holding captive in Gaza is in great danger due to his medical conditions, according to his son.

"We have no time," Mati Dancyg said about his father, who had a severe heart attack a few years ago and requires medication to prevent another. "Every minute that passes without this medicine is dangerous for him."

Alex Dancyg is believed to have been abducted from Kibbutz Nir Oz by Hamas during its brutal Oct. 7 attack when nearly half of the village’s 400 residents were kidnapped or killed, according to The New York Times

HOLOCAUST MUSEUM EDUCATOR HELD CAPTIVE BY HAMAS, SAYS SON

WATCH MORE FOX NEWS DIGITAL ORIGINALS HERE

Early on Oct. 7, Alex warned Mati, who was also in Nir Oz, about the terrorist invasion. That was the last time the younger Dancyg heard from his father.

"The last connection that we know of is my brother Yuval spoke with him after two hours after my talk at about 8:30," Mati said. "He told him the situation, ‘yes there are terrorists inside the kibbutz.’"

Mati said he's not entirely sure how the terrorists captured his father but said it's possible his father couldn't hold the door closed in his shelter. Like many shelters, intended for bombs rather than invaders, it didn't have a lock.

"The fact is he’s not there," he said. "He’s in a horrible place and again, the government should do everything that they can in the most urgent way that they can to bring him back home."

Alex Dancyg

Alex Dancyg is a longtime Holocaust educator who works with Yad Vashem. (Courtesy of Mati Dancyg)

JEWS RESPOND TO NEW YORK TIMES INITIAL REPORT ON GAZA HOSPITAL EXPLOSION: ‘HARASSED AND ABUSED BECAUSE OF IT’

Alex was born in Poland in 1947 — the year Israel was founded — to a family of Holocaust survivors. His sister Edith was saved as a baby in 1941 by a Catholic woman who was formally given the honorary title of "The Righteous Among the Nations," by Yad Vashem, Israel's official memorial to Holocaust victims.

"He was born in Poland to a family that somehow survived the Holocaust," Mati said. "I am so glad that they are not alive to see what happened."

When he was nine years old, Alex's family immigrated to Israel where he grew up to become a well-known Holocaust educator. Mati said his father is an expert on the Polish Jewish community and helped pioneer the common trips for young Israelis to see the Nazi death camps where their fellow Jews perished.

Map of kibbutzim near Gaza

Kibbutz Nir Oz is just one of the villages neighboring Gaza that was attacked by Hamas terrorists. (Fox News)

"Alex dedicated the past 30 years of his career to Holocaust education and remembrance, working with Yad Vashem as a guide in the educational department of the International School for Holocaust Studies at Yad Vashem," a spokesperson with the memorial group told Fox News.

"All of Yad Vashem's dedicated staff are praying for Alex as well as another Yad Vashem guide, Liat Atzili, also kidnapped nearly three weeks ago by Hamas terrorists during the massacre on October 7th," the spokesperson added. "We hope that all 220 hostages will be safely and swiftly reunited with their families who miss them tremendously."

THEY'RE 'CELEBRATING' A 'MASSACRE OF INNOCENT CIVILIANS': JEWISH COLLEGE STUDENTS DENOUNCE ANTI-ISRAEL PROTEST

In 2003, Alex guided a group of Muslim youth to Poland to learn about the Holocaust and to see the mass murder sites for Europe's Jews, according to the spokesperson.

Mati said he could only imagine what's going through his father’s mind as an expert on the Holocaust as he's held by a terrorist organization that calls for the destruction of the Jewish state.

"Sometimes it’s very hard to be Jewish," Mati said. "I think he’s thinking ‘we got through the Holocaust, we established a beautiful country but this thing is coming back now.'"

AMERICAN JEWS STEPPING UP: BOSTON COMMUNITY COLLECTS GEAR FOR ISRAEL DEFENSE FORCES

Mati’s wife and children survived Hamas' attack by hiding in their own shelter quietly for about 10 hours before the Israel Defense Forces escorted them to safety. Mati’s 71-year-old mother — Alex’s ex-wife — was also in the Kibbutz and survived with her two granddaughters by holding the handle of the door shut while terrorists tried to break and shoot their way in.

Poland’s Jewish community is also alarmed about Alex's kidnapping, according to Anna Różańska, who is helping raise awareness with graffiti of Alex on the streets of Warsaw.

Alex Dancyg graffiti

Anna Różańska said the graffiti to raise awareness on Alex's captivity is "the only way to wipe away our tears." (Courtesy of Anna Różańska)

"The graffiti is to put light on this exceptional man promoting dialogue and peaceful regard between Polish and Israeli people," Różańska told Fox News. "For us, graffiti is the only way to wipe away our tears."

CLICK TO GET THE FOX NEWS APP

"Today the most urgent message is to pass to Alex: ‘your family is alive!’" she said. "This would give him strength to survive."

Różańska also said she is worried about Alex not having access to his medication.

Isabelle McDonnell contributed to the accompanying video.