Residents in north-western Nicaragua were on alert Sunday after the San Cristobal volcano began erupting, sending a plume of ash and gases 4,000 metres high. Authorities had ordered the evacuation of about 3,000 people living on the skirts of the 1,745-metre volcano in the provinces of Chinandega Leon. Vehicle traffic near the Honduran border was paralyzed due to the heavy fallout of ash. Civil aviation officials closed flight paths in the area of the eruption, according to a report of dpa.