Seismologists in Congo on May 29 recorded 61 earthquakes per day around the Nyiragongo volcano, which erupted a week ago. 

Officials warn of a second eruption, CNN reported.

A daily report prepared for the government by the Goma Volcanic Observatory explains that the volcano's crater continues to collapse, contributing to earthquakes and causing ash emissions visible from Goma. A provincial government spokesman said on Friday that some 400,000 people have fled the city, with the first blast last weekend killing at least 31 people and missing hundreds of children.

Since then, the area has experienced a series of earthquakes and tremors, some of which were felt more than 100 km away from the volcano.