Officials confirmed Friday that a former Brooklyn rabbi and his wife were among five killed hostages killed in an ultra-orthodox Jewish center in Mumbai, India that was held under siege that morning.

Gavriel Holtzberg, 29, and his wife Rivka, seen above, as well as Brooklyn resident Leibish Teitelbaum were found in Mumbai's Chabad-Lubavitch Jewish Community Center, following a two-day attack by militants.

A day-long effort to flush out militants believed to be holed up inside the headquarters of the Jewish outreach group ended Friday morning. Sources told NY1 that police took over two floors of the center, and that the struggle ended when a massive explosion rocked the center, which appeared to have been part of the commando assault on the building.

In New York, Police Department spokesman Paul Browne said Friday that security was increased at the city's Lubavitcher center, as well as at Jewish centers and large hotels.

"This is indeed a very sad day," said Police Commissioner Raymond Kelly said at a Friday afternoon conference in Crown Heights. "It is a reminder to all of us just how connected we are."

Rabbi Yehuda Krinsky of the Chabad-Lubavitch movement confirmed the Holtzbergs' death at the conference and wiped tears from his eyes as he described the rescue of the couple's young son.

"The Holtzbergs' toddler son, Moshe, [who] was heroically rescued from the hell by his nanny Sandra, will mark his second birthday tomorrow, Saturday, November 29th," said Krinsky. "Today, he became an orphan without a dad and mom to lovingly embrace him and celebrate with him."

Krinsky said the couple had another son, who is not in the Mumbai center and is currently safe.

According to the Chabad-Lubavitchers, the Holtzbergs were in Mumbai since 2003 to serve the city's small Jewish community, founding a Chabad House to teach mentor and help the needy.

Lubavitcher Rabbi Moshe Kotlarsky also became emotional as he described Holtzberg, who he called a close colleague.

“In the most trying of times, he always wore a smile,” said Kotlarsky. “He was a real ‘mensch’ [honorable man]. We're going to miss him very dearly. He was a very, very special person, him and his wife - very, very special people."

Members of the Chabad community then held a prayer service for the Holtzbergs immediately after the conference, to allow the tight-knit religious community to cope.

"It's devastating. It's just a tragedy and it's hard to believe that would happen," said resident Yossi Bendet.

"It's a terrible, terrible tragedy. It's really a tragedy for all mankind, not just the family, not just the Jewish people," said local Menachem Frietfertig.

Also on Friday, the State Department confirmed that another U.S. citizen and his daughter were killed while traveling Mumbai with a group from the Synchronicity Foundation, a Virginia-based group that studies holistic meditation.

The group identified the victims as Alan Scherr, 58, and his 13-year-old daughter Naomi.

Meanwhile, Indian forces were still battling militants at the Taj Mahal hotel in Mumbai Friday night.

Commandos were launching grenades at the Taj, where at least one militant was believed to be holed up inside a ballroom Friday night.

About 400 people were rescued from the Taj Thursday.

Meanwhile, security officials say commandos now control the Oberoi hotel, after killing two gunmen there and after finding at least 24 bodies inside.

Dozens of hostages were rescued from the hotel yesterday.

The violence started Wednesday, when terrorists launched coordinated attacks on 10 locations, including a cafe, theater and train terminal.

As of Friday night, it was estimated that 150 people were killed and nearly 400 were wounded.

Authorities did not know Friday night who was responsible for the siege, but India's foreign minister said "elements in Pakistan" were behind the attacks.

No motive had been established by Friday.

Kelly said Friday the NYPD is not familiar with the terror group that claimed responsibility although he said it might be a coalition of several terror cells.

He said the NYPD may send officers to India to gather intelligence, as happened after Mumbai's 2006 bombings.

A U.S. investigative team is headed to Mumbai, and the State Department urged Americans not to travel to the city, at least through the weekend.