A volcano in the Democratic Republic of Congo has seen some "strong activity" and could erupt in the next few days, the Volcanic Observatory in Goma said on Friday.

Experts said seismic activity at Mount Nyamulagira, in the east of the country, does not currently pose any risk to the local population, although Goma, a city of over a million people devastated by an eruption in 2002, sits just 20 kilometres (12 miles) away.

Scientists said the volcanic activity should not affect the neighbouring Nyiragongo volcano, which erupted 12 years ago.

"The Nyamulagira volcano has entered a period of high activity, which could lead to an eruption in the next few days," Kaso Karume, a volcanologist at the institute told AFP.

He said the scientists believe it "will not have any effect on the Nyiragongo volcano, where activity is normal".

"Since lava from Nyamulagira normally feeds into (the nature reserve) Virunga, there is no danger for inhabitants of Goma and those nearby," he said.

Goma, which sits on the border between the DRC and Rwanda, is perilously positioned beneath the two volcanoes. The 2002 eruption saw rivers of molten rock destroy buildings and leave thousands of people homeless.

The red glow of the lava lake -- which can be seen from Goma by night -- reminds residents that they live at the foot of one of the most active volcanos in Africa.

Lava and debris from the most recent eruptions in the area -- in 2004, 2006, 2010 and 2011 -- did not reach populated areas, although volcanic ash can pollute the atmosphere over a wide area.