CHARIKOT, Nepal — Nepal has been overwhelmed by its second massive earthquake in less than three weeks, its prime minister said today as he visited this normally placid foothills town, now a center for frightened villagers desperate for government help.

Thousands of people now crowd the streets of Charikot, the administrative center of the isolated district hit hardest by Tuesday’s magnitude-7.3 quake, which killed at least 96 people and injured more than 2,300. The magnitude-7.8 earthquake that hit April 25 killed more than 8,150 people, injured tens of thousands more and left hundreds of thousands homeless.

“After the first quake, we were not prepared for a second one so big,” Prime Minister Sushil Koirala told reporters.

He said the coming monsoon rains now loomed large, with hundreds of thousands of people left homeless.

“We need tents. Our people need shelter. With the rainy season, it will be difficult for people to survive in the open,” he said.

Nearly everyone is too afraid to sleep indoors in Charikot, which is filling with people from surrounding areas seeking help. Aftershocks are keeping them on edge. Charikot is 85 miles north of Kathmandu, the Nepalese capital.

While food has been handed out occasionally here, supplies were nowhere near enough for the people who kept arriving.