Nicaraguan government forces launched intense raids backed by heavy equipment on Sunday in three rebellious towns, south of the capital, leaving scores of people injured after another bloody week of uprisings.

Residents and rights groups said troops used mechanical shovels in the early hours of the day to clear barricades in three towns near Masaya, attacking their defenders in the latest violence convulsing the Central American country.

Monimbo, in southern Masaya department, has been the epicenter of resistance against the government of President Daniel Ortega since a wave of student-led protests began April 18 over a since-aborted pension reform plan.

Since then, violence has claimed at least 272 lives.

"The situation is serious," said Alvaro Leiva, secretary of the Nicaraguan Association for Human Rights (ANPDH). "We need to open a corridor to evacuate the wounded."