PORT-DE-PAIX, Haiti — Survivors sifting through the rubble of their earthquake-toppled cinderblock homes in Haiti on Sunday were rattled by a magnitude 5.2 aftershock that caused panic and threatened to raise the death toll even further from 12.

The U.S. Geological Survey said the epicenter of the aftershock was located 9.8 miles north-northwest of Port-de-Paix, the city hard hit by Saturday night’s 5.9 magnitude earthquake. Sunday’s aftershock had a depth of 10 kilometers.

“It was an aftershock. It was at the same location,” said Paul Caruso, a geophysicist with the USGS. “This is the first significant aftershock.”

The tremors caused panic on streets where emergency teams were providing relief to victims of Saturday’s quake, which toppled cinderblock homes and rickety buildings in several cities.

Haiti’s civil protection agency said at least seven people died in the coastal city of Port-de-Paix and three people died in the nearby community of Gros-Morne in Artibonite province. Among the dead from Saturday night’s quake were a 5-year-old boy crushed by his collapsing house and a man killed in a falling auditorium.

A total of at least 12 people were killed in the quake, Interior Minister Fednel Monchery told radio station MAGK9. Authorities said 188 people were injured.

“I feel like my life is not safe here,” said nun Maryse Alsaint, director of the San Gabriel National School in Gros-Morne, where several classrooms were severely damaged.

She said that about 500 students would not be able to return to school on Monday.

The prison and police station in Port-de-Paix were damaged, leading some inmates to try to escape. Police were using tear gas to contain prisoners inside the lockup. There was no word if any inmates had escaped.