Two-year-old Zainab Mughal, a South Florida girl, is battling neuroblastoma, an aggressive cancer.

Little Zainab is in need of blood transfusions and bone marrow transplants. But she has an extremely rare blood type. Donors who match it have been a challenge to find.

OneBlood, a nonprofit blood center, is conducting an international search to find donors that match Zainab's rare blood type.

The little girl's red blood cells are missing a common antigen that most people carry called Indian B. For a donor to match her blood, he or she must have the O or A blood type and have the same missing antigen — or Zainab's body will reject the blood.

The only donors statistically likely to be a match for Zainab are those of Pakistani, Indian or Iranian descent, according to a OneBlood press release. That means a donor's birth parents must both be 100-percent Pakistani, Indian or Iranian.

And even of those populations, less than 4 percent are missing the Indian B antigen like little Zainab, the release states.

Zainab's parents' blood isn't compatible either, her dad Raheel Mughal said in a OneBlood video.

According to the Dec. 3 release, more than 1,000 local and nationwide donations have been tested. Only three have been identified — including one as far as London — and more donors are needed.

"It's not enough," said Raheel Mughal said in a video pleading for help. "We need to find more... It's a humble request, and I request it from my heart. My daughter's life very much depends on the blood. So, please, donate the blood for my daughter."

Donations are being coordinated by OneBlood for compatibility testing.

If heading into a OneBlood donation center, the prospective donor must specify that he or she is looking to donate for Zainab, so that staff can tag the blood for testing.

Visit oneblood.org/zainab for donation instructions.

Reach Nada Hassanein at nhassanein@tallahassee.com or on Twitter @nhassanein_.