MANAGUA, Nicaragua — The hundreds of hot dog buns, bananas and containers of instant soup stacked up at the Polytechnic University basketball court suggest that the young people hunkered down here are not planning to capitulate.

The students and young professionals who occupied the campus last week in a nationwide protest against the government, demanding the ouster of President Daniel Ortega, have enough donated medical supplies to stock a field hospital. Young men with T-shirts covering their faces carry homemade mortar-launchers as they patrol the grounds. A box of Molotov cocktails sits in the corner.

“This is not a war; this a struggle we young people are doing,” said Freddy Martínez, one of the few people here who revealed his face and name. “We are not left or right. We are Nicaragua.”

The Nicaraguan youth did something few people in this country thought possible. Incited by an unpopular change in the social security system that would not immediately affect them, they staged a spontaneous uprising that has loosened Mr. Ortega’s sweeping grip on power.