ISLAMABAD, Pakistan  The International Islamic University here, one of the country’s premier schools, prides itself as a unique center of learning that combines “the essentials of the Islamic faith with the best of modern knowledge,” as its Web site says.

So on Tuesday afternoon, when two suicide attackers struck this conservative gender-segregated campus simultaneously, killing six people, many of the students and residents of Islamabad were perplexed.

The attackers’ bombs ripped through a cafeteria for female students, two of whom were among the dead, and destroyed an office in the Shariah and law department in a second building. Dozens were wounded.

“When I heard that it was Islamic University, I wondered why an Islamic institution would come under attack,” said Erum Yasir, 32, who was visiting Islamabad from her home in New Jersey.