WASHINGTON - In two decades as a Baptist missionary in the Middle East, Mike Edens has had a lot of opportunity to worry that he and his family could become a target of anti-American passions and violence.

Yet whenever he wondered whether he should leave his post, he always came to the same conclusion: "It's much wiser and safer to be obedient to God and do his work than to do otherwise."

Edens' attitude helps explain why the number of U.S. evangelical missionaries has increased steadily in the Middle East in recent years, even as a radicalized, anti-American form of Islam has raged across much of the region.

And although the U.S. government has warned that al-Qaida and groups associated with the terror network are targeting Americans abroad, thousands of missionaries continue to serve in remote, impoverished areas of the Arab world.

Usually unguarded, they present the sort of soft target that U.S. intelligence agencies have warned that terrorist groups are seeking out.

Despite the dangers, the growing U.S. evangelical community has decided the region needs the benefits of Christian teaching more than anywhere else. And the missionaries insist they are staying there, although their proselytizing can ignite dangerous frictions.

The risks were demonstrated again Monday, when a gunman with a concealed rifle entered a U.S. missionary hospital in Jibla, Yemen, killing three missionaries and seriously injuring a fourth. Even as the Southern Baptist Convention mourned the loss of its members, it vowed to remain in Jibla as long as the Yemeni government allows.

"We're committed to maintaining whatever ministry we can in the country," said Jerry Rankin, president of the Southern Baptist Convention's International Mission Board.

While precise numbers are elusive, observers from U.S. churches estimate the number of American missionaries who live in the Middle East is probably now in the low thousands. Ten years ago, the figure was probably in the high hundreds, they say.

The number includes missionaries from the new wave of evangelical groups, as well as from others that have long had a presence in the region, such as the Roman Catholic Church, the American Friends Service Committee and the Mennonite Central Committee.

Periodically, the State Department warns U.S. missionaries that it cannot guarantee their safety in remote and dangerous parts of the Middle East. Those warnings have increased since the Sept. 11 attacks, and at least some missionaries have decided to return to the United States.

And since Sept. 11, most missionary groups have worked out plans for quickly evacuating workers.

The most sensitive question missionaries face is how active they will be in trying to bring Muslims to Christianity.

Although proselytizing is usually forbidden, most countries in the region are eager to have Western religious groups running hospitals and clinics and working on economic development and education.

Some long-established missionary groups in the Middle East have come to terms with this by focusing their work on serving the social needs of the local population, and hoping they might draw Muslims to Christianity more indirectly, through example.

But other missionaries, including many evangelicals, feel that it is part of their faith as Christians to try to spread the Gospel.

Sometimes, these efforts have led not only to friction with Muslims, but also with other Christian missionary groups, which fear that such efforts put them in danger and their work in jeopardy. Sometimes there are frictions, too, with indigenous Christian denominations, such as the Orthodox and Copts.

Some Islamic groups complain the missionaries are taking advantage of the Muslims' needs.

"They go into poor areas, and they take advantage of their power," said Ibrahim Hooper, a spokesman for the Council on American Islamic Relations, a civil rights group in Washington. "They hold a blanket in one hand, and a Bible in the other, and say you can't get one without the other. ... It's the deceit I don't like."