KARMIDA, Morocco — Amina el-Filali, a moon-faced Moroccan peasant girl, seemed destined for an obscure life in this dreary little farming village 50 miles south of Tangier.

But that was before she was lured into sexual relations at age 15 by a 23-year-old unemployed laborer who took her into a shed next to the eucalyptus grove behind her house. That was before she was ushered into an early wedding, with the man who took her virginity, by a traditional Muslim family eager to salvage its honor. And that was before she swallowed rat poison to commit suicide rather than endure what she told her mother was an unbearable marriage.

Since Amina took her life shortly before lunch March 10, she has become a national cause, an icon for women’s groups, human rights organizations, progressive politicians and millions of ­Western-oriented Moroccans who have demanded changing a law that permits marriage at such a young age.

The law under attack is based on Islamic jurisprudence and tradition. As a result, the demands for change present a particularly unwelcome challenge to Morocco’s new Islamist government, which was elected in November on a promise to make Morocco more Islamic — not less.

The quandary faced by Prime Minister Abdelilah Benkirane and his Justice and Development Party, Morocco’s main Islamist group, has high stakes for Morocco, which depends heavily on European tourism and thus on its reputation abroad.

But it is emblematic of tensions emerging in places such as Egypt, Tunisia and Libya, where Islamic groups rising to positions of power in the aftermath of the Arab Spring are beginning to confront pressures pitting principles imported from the West against their Islamic traditions.

“Little girls raped in their village — it happens all the time,” said Khadija Ryadi, head of the Moroccan Human Rights Association in Rabat, the capital, about 100 miles south of here. “But it was important this time, because everyone is waiting to see what the reaction of an Islamic government will be.”

The demands for change have arisen only eight years after a landmark modernization of the country’s family code, spearheaded by King Mohammed VI. That effort was widely hailed — by the United States, the United Nations, European governments and human rights groups — as a triumph for the then-newly crowned king and an example for the rest of the Arab world.

The family code, or mudawana, set 18 as the legal age for marriage for both sexes. But it also provided for exceptions to be decided by judges on the basis of special legal and social circumstances. In practice, the provision robbed the age limit of much of its meaning; the Justice Ministry estimates the number of such exceptions at about 35,000 a year.

Now the uproar set off by Amina’s case has led to an effervescent Internet reaction in Morocco, with loose allegations of rape and demands for immediate change, including a Facebook site named “We are all Amina” and a deluge of tweets repeating the slogan.

Anti-rape demonstrations have been staged in the largest cities, attended mainly by women. The U.N. office in Morocco declared that marriage laws should be modernized, and the left-wing Socialist Union of Popular Forces party has petitioned for a parliamentary investigation mandated to recommend amendments.