The Nicaraguan Humanitarian Rescue Unit (UHR) Wednesday rescued two university students who had been trapped under tons of cement and iron after a 7.3-magnitude earthquake shook Haiti last week.

General Mario Perezcassar, chief of the UHR, told local TV channel Canal 4 that the two female students, 19 and 21 years old, were found in the basement of a university in Port-au-Prince.

"After almost eight days, it is almost a miracle. For us it was a great satisfaction because we thought that we would not find anybody else alive," Perezcassar said.

Perezcassar added that the UHR had rescued six of the 75 survivors found by the international rescue teams since Jan. 14.

According to Perezcassar, the 6.2-degree aftershock that shook Port-au-Prince on Wednesday morning "was really strong." He said it caused "collective hysteria" among the public, who were still traumatized by last week's earthquake.

Nicaraguan President Daniel Ortega said on Tuesday that his government is considering the possibility of extending the rescue team's mission in that Caribbean country to aid the victims.