Technical difficulties during a 24-hour, online giving campaign, sponsored by United Way of the National Capital Area, frustrated organizations and donors alike Thursday, resulting in an extension of the effort into Friday.

The campaign, called “Do More 24,” combined events across the region with online fundraising scheduled to last just one day. Donors were asked to give at least $10, in hopes of raising more than $2 million for the nearly 1,000 area nonprofit organizations involved.

But heavy traffic on the Web site, domore24.org, caused slow transaction speeds, according to Michael Altman, senior vice president of marketing and communications for United Way of the National Capital Area. At one point, the Web site was handling more than 100 donations a minute, he said.

The campaign has been extended until 11:59 p.m. Friday, and United Way will donate an additional $24,000 more in prize money — on top of $75,000 it had already pledged — to nonprofits groups that have the most donors and dollars raised in various categories.

Homeward Trails Animal Rescue won $5,000 in the first contest Thursday by getting 306 donors by noon.

Sue Bell, the organization’s founder and executive director, had expected the fundraising frenzy to be over by midnight Thursday. Now she has to rally her staff, volunteers and donors on Friday to meet their goal of $30,000.

“We have very mixed feelings now,” Bell said. “This is emotionally taxing on all the participants.”

Homeward Trails, which is based in Arlington, was fielding questions from donors about the Web site’s problems.

“It wasted a lot of our time,” she said.

As of 8 p.m. Thursday, Homeward Trails had raised more than $14,000.

Molly Whalen, director of development and communications at the Ivymount School and Programs in Rockville, said she was directing people to the special-education school’s Web site to donate.

“When you have people who are donating, you want to make the process easy,” Whalen said. “I don’t want to lose a single donor because they’re trying to tap on the keys and it’s just not going anywhere.”

But redirecting those dollars to the school’s Web site meant potentially losing out on prize money through the “Do More 24” contest categories.

An additional 24 hours to fundraise will be difficult for the school, she said, because they weren’t anticipating a second day. “I just think extending it really isn’t much of a help,” Whalen added.

United Way’s Altman said he understood the frustration.

“I don’t blame people for being upset,” he said.

A third-party hosting company was caught off guard with the huge spike in traffic, Altman said.

“Unfortunately, the technology did not stand up to the crowd,” he said, adding that it’s not an uncommon problem with crowdfunding.

“We think that the overwhelming response is a very positive thing,” Altman said.

As of 8 p.m., more than $792,000 overall had been raised, according to the Web site.