Pope Francis ventured Friday into a violent, overcrowded and gang-ridden Bolivian prison that even houses small children living with their parents, and urged inmates not to despair.

If other events on the pope's three-nation tour of South America were joyous ones -- million-strong crowds of worshipers singing and praising the pontiff -- the trip to Bolivia's most dangerous prison was arguably a humbling descent into hell.

Pope Francis demanded an immediate end Thursday to what he called "a genocide" of Christians taking place in the Middle East and beyond, describing it as a third world war.

The pope, who has never been afraid to weigh into delicate issues both religious and political, made the comments in Bolivia, the second stop on a three-nation tour to his home continent of South America.

Bolivian authorities said they've seized 27 metric tons of shredded coca leaves that were to have been shipped to Lebanon for processing into cocaine.

It was labeled as yerba mate, a caffeine-rich tea that is especially popular in Argentina and Uruguay. That's according to deputy social defense minister Felipe Caceres. He told reporters that Monday's seizure was a first.

A strong 6.6-magnitude earthquake Monday struck the Santa Cruz islands, part of the Pacific's Solomons group, the USGS said, but there was no threat of a widespread tsunami, according to officials.

The quake hit at a depth of 38 kilometers (23 miles) at about 3:00 pm (0400 GMT) some 350 kilometers (220 miles) east of Kirakira, the main city of the Solomons' major island, Makira.