Congregations at churches near the site of the fatal building explosion in East Harlem, joined by local elected officials, on Sunday mourned the victims through prayer and vowed to strengthen community ties to help in the healing process.

Bethel Gospel Assembly lost two congregants in the Wednesday blast, fire and building collapse -- Carmen Tanco, 67, who served as an usher, and Griselde Camacho, 45.

The church pastor, Bishop Carlton T. Brown, acknowledged to about 300 assembled Sunday that the pain of separation was deep. He led prayers for Spanish Christian Church, located in one of the two collapsed buildings.

Mayor Bill de Blasio, his wife, Chirlane McCray, Rep. Charles Rangel (D-Harlem), City Council Speaker Melissa Mark-Viverito, Public Advocate Letitia James and the Rev. Al Sharpton were among the high-profile guests at the church service.

De Blasio thanked the church for its support of the community and said Tanco and Camacho got the most from life because they gave to others.

"You can feel the support here. . . . You can feel how tangible and real it is," said the mayor.

"We've been tested this week, but we're going to rise . . . " Sharpton said. "We are stronger than even the explosion we faced."

McCray announced that the Mayor's Fund to Advance New York City, which she chairs, has secured $250,000 to help blast victims and their families.

"If there's one thing New Yorkers can count on when there's a crisis, it's other New Yorkers," McCray said.

Later, at the Church of God, at 2135 Third Ave., just two blocks from the site of the blast, de Blasio and Mark-Viverito addressed the 200 or so congregants in both English and Spanish. The church was hosting congregants of the demolished Spanish Christian Church.

The mayor thanked volunteers, community members and first responders, lauding their bravery and sacrifice.

"In this tragedy is an example to us all of the love that permeates this city. . . . Sometimes it's hard to see. Sometimes this place seems a little tough. But underneath, we have each others' backs," he said.

De Blasio reiterated that the city would find permanent housing in East Harlem for those residents who have been displaced by the blast, thought to be caused from a gas leak.

He received a standing ovation when he said aid would be available to undocumented immigrants.

"We are here to help everyone regardless of their documentation status," he said, "because they're all our brothers and sisters."

When firefighters and police arrived at the explosion, "they didn't say, 'Can we see your papers?' " de Blasio said.

Meanwhile, at the blast site, about a dozen members of St. Paul's Roman Catholic Church, on East 117th Street, nearby, gathered near the explosion to pray and sing.

"I feel bad about what happened" said Josefa Garcia, 71, a parishioner who was helping to lead the singing. She said she knows those who died are in "heaven already."

"God has mercy on everybody," Garcia added: "We are Catholic; we believe in God. When we believe in God, we have to pray.

"We believe in prayers," she said.

At the site, a bulldozer scraped away debris and clumps of earth. Officials from Con Ed and the FDNY, along with at least one representative from the National Transportation Safety Board were seen gathered together Sunday.

Earlier, the NYPD escorted a busload of residents who had been evacuated from their East 117th Street building to collect belongings from their homes. Their building is near the explosion site.

Firefighters were also at the site. FDNY Commissioner Salvatore Cassano said Saturday that the focus of the investigation would shift Sunday to the gas pipes and meters in the basements of the buildings -- once debris had been removed to give access. But Sunday investigators released no information on any work in the basement and declined to say whether it had been made accessible.

Speaking to reporters later Sunday de Blasio said: "As of yesterday, we were still in a recovery mode. I have not heard anything yet that suggests otherwise. We were hoping that the rescue teams and the first-responder teams could get into the basement and get us some more information as early as today, but as I've said . . . Expect this to be an ongoing investigation for quite a while.

Reiterating what he said in church, he also emphasized to reporters the need for affected residents to register for government assistance, saying "As of yesterday, there were dozens of families that had not registered for help. We fear that some of them are worried about registering because of their immigration status."

The National Transportation Safety Board had also arrived last week to do its own probe of the blast.