Dozens of Gaza Christians staged a rare public protest Monday, claiming two congregants were forcibly converted to Islam and were being held against their will.

The small but noisy demonstration showed the increasingly desperate situation facing the tiny minority.

Protesters banged on a church bell and chanted, "With our spirit, with our blood we will sacrifice ourselves for you, Jesus."

Gaza police say the two are staying with a Muslim religious official at their request, because they fear retribution from their families converting to Islam. Two mediators said the two - a 25-year-old man and a woman with three children - appeared to have embraced Islam of their free will. Forced conversions have been unheard of in Gaza before.

Since the Islamic militant Hamas seized power five years ago, Christians have felt increasingly embattled, but have mostly kept silent.

There are growing fears among Gaza Christians that their rapidly shrinking community could disappear through emigration and conversions.

Their numbers appear to have shrunk from some 3,500 to about 1,500 in recent years, according to community estimates. They are a tiny minority among 1.7 million Palestinians in Gaza, most conservative Muslims.

"If things remain like this, there'll be no Christians left in Gaza," said Huda Al-Amash, mother of one of the converts, Ramez, 25. She sat sobbing in a church hallway alongside her daughters, Ranin and Rinad, and a dozen other women. "Today it's Ramez. Then who, and who will be next?"

Christians said the main reason for the shrinking numbers is emigration, since there are few jobs in Gaza.

Changing faith is a deeply traumatic affair in the Arab world, where religion is strongly interwoven with people's identities and tribal membership.

To convert often means to be ostracized by the community.

The two converts, Al-Amash, and Hiba Abu Dawoud, 31, could not be reached for comment. Abu Dawould took her three daughters with her, further enraging the community.

On Monday, groups of men and women stood in groups in the square of the ancient Church of Saint Porphyrius, angrily chanting," Bring back Ramez!" One man angrily hit the church bell.

"People are locking up their sons and daughters, worried about the ideas people put in their head," said Al-Amash's mother, Huda.