CureFest attendees are seen at Lafayette Square on Saturday near the White House. (Courtesy Mike Gillette)

The head of the Secret Service apologized for how a group of children suffering from cancer and their supporters were treated after they said they were pushed out of Lafayette Square on Saturday night.

Joseph Clancy, director of the Secret Service, called one of the organizers on Monday after CureFest for Childhood Cancer said that about 700 parents and children were ordered out of the park in front of the White House for at least two hours. The move disrupted their plans for a candlelight vigil to raise awareness and research funding for childhood cancer.

Mike Gillette, one of the group’s organizers and a documentary filmmaker in the Fairfax area, said Clancy called him Monday and said that he was “very sorry” and that the agency “did not handle the situation well.” A spokeswoman for the Secret Service confirmed that Clancy made the call and said the agency plans to review some of its policies on closures.

According to Gillette, Clancy offered to come to one of the group’s events to apologize in person and offered to have some of the children come to one of the agency’s training facilities in Maryland for a tour.

“He said he would do whatever he could to make up for it,” Gillette said.

The incident began Saturday when many of the group’s organizers said they were hurt and disappointed that the Secret Service and U.S. Park Police, citing security precautions, virtually shut down what they considered the highlight of their two-day event. It was the second time that day that the group had been asked to leave the area.

“We ended up waiting at the gates for two hours, and they never let us in,” said Natasha Gould, an 11-year-old from Canada who started a blog after being diagnosed with an inoperable brain tumor this year. “And to be clear, the entire crowd was half kids. I cried last night in my hotel room because it was my first CureFest, and I couldn’t believe people were acting like they don’t care about children.”

“Closures of Pennsylvania Avenue and Lafayette Park on Saturday, September 19, 2015, were performed in accordance with security protocols for protectee movements in the vicinity of the White House,” Sgt. Anna Rose, a Park Police spokeswoman, said in an e-mailed statement. “The United States Park Police empathizes with the organizers and participants of CureFest and appreciates their understanding. We hope going forward to better communicate with CureFest and other groups effected by security protocols.”

Closures of Lafayette Square have occurred periodically since the attacks of Sept. 11, 2001, and during security incidents at the White House.

In a statement e-mailed late Sunday, Brian Leary, a spokesman for the Secret Service, said the closures on Pennsylvania Avenue and Lafayette Square were “put into place based on standard [Secret Service] protocols prior to protectee movements in the vicinity of the White House Complex.”

He added, “The Secret Service would like to express its regret for not communicating more effectively with this group concerning the timeline for protectee movements in the vicinity of Lafayette Park.”

On Monday, Nicole Mainor, a spokeswoman for the Secret Service, said that Clancy did call Gillette and apologize but that she did not know exactly what was said.

“We can confirm that as a result of what happened this weekend, the [Secret Service] is reviewing protocols regarding closure protocols and any related communications.”

She would not comment on whether she believed the agency handled the incident properly.

Organizers, aligned with the Truth 365 grass-roots child-cancer advocacy program, said they had obtained the necessary permit a year ago to hold “A Night of Golden Lights,” in which participants would light about 100 battery-operated candles.

Gillette said the group was asked to leave Lafayette Park on Saturday afternoon.

“We were told that it was related to movement from within the White House,” he said.

The group left the area, he said, and they were let back onto the grounds after about 40 minutes.

Gillette said a ranger with the Park Service had told them earlier in the day that there was a chance that the president was going to go back out again.

“She said, ‘We want you to know that,’ ” Gillette said. The ranger also told him that “if he uses one of the different exits, it would not impact your event.”

But she warned that “you may be disrupted again,” Gillette said. “We were aware of that and we were prepared for that . . . for a temporary disruption.”

About 7:15 p.m., just as the group was about to kick off the centerpiece of their event — with music, speakers and more guests coming from the nearby JW Marriott hotel — they were told that they had to get off the grounds again.

“Everything was in perfect position and we had to leave,” Gillette said. “We had families from all over the country and from different countries.”

“We were asked to leave the barricaded area,” he said. “They [the Secret Service] didn’t say why.”

The group — which had drawn people from 40 states, along with Scotland, Canada and Australia — complied.

Gillette said they waited “and waited and waited” outside the barricaded area. He said the Secret Service agents on the scene were “professional and polite.”

“They couldn’t provide us with much information but kept saying it shouldn’t be much longer,” Gillette said.

He said some people in the group had close friends and family in the Secret Service, and, after roughly 90 minutes, they started to make calls and found out that the Secret Service had decided that it would close the park for “however long it took for the president to return.”

But as the closure continued, some of the sick children, fatigued by the wait or the need to receive medication, had to return to their hotel rooms, organizers said. Others began crying, and some parents became enraged. Attendees said the group was not allowed access to personal items they left behind, such as chairs and blankets.

Police officers and agents at the scene told some parents that the closure was necessary because President Obama had left the White House from an entrance near the square to address the Congressional Black Caucus Foundation’s annual gala.

“At first, we were patient. I mean, we’re a peaceful community; we’re fighting for kids’ lives,” said Anthony Stoddard of New Hampshire, who, after the death of his 5-year-old son, started an initiative to light public buildings in gold as a show of support for children who have cancer. “But after about an hour, or hour and a half, it started getting a little angry, some of the fathers.”

Some parents considered the park closure excessive, perhaps driven by the agency’s embarrassment over previous high-profile security lapses. Others read into it signs of a White House snub of their cause.

“I feel like this may be overcompensating for glaring errors that the Secret Service has made in past years. And again, we understand the need to keep our president safe. But we think a little consideration would have gone a long way,” Gillette said. “When we get shut out of the president’s front yard, it’s just disheartening.”

The candlelight vigil came about partly because of the group’s inability to persuade the White House to light up the mansion in gold as a symbol of support for the cause, as it has done for other causes, organizers said. So they decided to hold a candlelight vigil of their own. Last year was the first.

When the group was in Lafayette Square last September for their event, they said that authorities were dealing with an incident around the same time in which someone had tried to breach security at the White House but it had no effect on their activities.

“It’s ironic our event is interrupted by routine travel by the president,” Gillette said. “Last year, someone jumped the fence at the White House and we had no problems.”

On Saturday, the group said it had a permit to stage its event from 4:30 p.m. until 9 p.m.

Around 9:15 p.m., the crowd started to dwindle because it was apparent that there was “no end in sight” to the waiting, Gillette said. Organizers started to do a makeshift program outside the security perimeter near H and 16th streets NW.

The event lasted about 20 minutes.

“It was disheartening,” Gillette said. “There were families who came from all over the country to honor their children, and this moment meant a lot to them.”

He said there were also kids — who did not have cancer but who were “looking forward to performing.”

“It was very disappointing to see the looks on their faces,” he said.

Many of the kids ended up performing on the street, illuminated by cellphone flashlights instead of being on a professional stage with lights.

By the time the group got back into Lafayette Square around 10:30 p.m., organizers said, only a handful of supporters were left.

“It got really frustrating,” Stoddard said. “No one was giving us answers about when we would get in.”

“So finally, about 10:30, we gave up,” he said. “It was heartbreaking.”