AN earthquake measuring 5.3 magnitude rocked the borderlands between Rwanda and Congo this morning, the Rwandan Seismic Monitor said, raising worries about a fresh eruption following one on Saturday that killed at least 32 people. On Saturday Democratic Republic of Congo's Mount Nyiragongo, one of the world's most active and dangerous volcanoes, erupted sending a river of lava downhill towards Goma, a city of some two million people. The area has experienced repeated tremors since then, and the lava lake in the volcano's crater appears to have refilled, raising fears of new fissures or another eruption, the United Nations Refugee…