Attempts to complete the evacuation of more than 3,000 residents from communities near the 9,700-foot Copahue Volcano in Chile were hampered by arguments over the evacuees' livestock and the animals' safe transit.
Farmers with scant personal possessions other than cattle and other farm animals challenged evacuation plans.
Long delays were made worse by heavy rainfall and snow, The Santiago Times in the Chilean capital reported.
Some evacuees reached the town of Ralc near Copahue and the Ralco National Reserve in the central Chilean region of Bio Bio.
Officials warned the volcano could erupt any time after a series of tremors and gas clouds from the crater hit the area.
Chile's National Geology and Mining Service said it recorded an "upward trend" in seismic activity in the volcano.
Both governments issued a "red alert" as they set about evacuating people from localities near the volcano. More than 600 people were ordered to leave Argentine villages and towns near the Copahue, including the Patagonian ski resort of Caviahue in Argentina.
"This evacuation is obligatory, it's not voluntary," Chilean Interior and Security Minister Andres Chadwick said.
Safety measures have included evacuation of people and farm animals within a 15-mile radius of the volcano.
The Copahue volcano was last active in December but went quiet after several gas eruptions. The affected area overlaps Chile's Bio Bio region and Argentina's Neuquen province.
News of the volcano was overshadowed in Argentina by anti-government demonstrations and strikes. Protesters are demanding income tax reforms and rise in pensions and wages.
Gov. Jorge Sapag of the Neuquen province said, "The volcano will have the last word" and urged everyone not to speculate about the eruption might start.
He defended the governments' decision to issue a red alert, which was a response to the experts' reading of the volcanic activity.
"The decision to shift to red alert evacuation was a wise (one), because the magma is rising," Sapag told news media.
He said "microearthquakes are still occurring, a critical mass is rising through the conduit of the volcano, so we have to be attentive to see if the final process of the volcano is solid, liquid or gaseous," MercoPress reported.
Copahue had a major eruption in 1992, Chilean Mining Ministry data indicated. The volcano began stirring again in 2002, its strongest activity in more than 20 years, weather.com reported on its website.
About 500 of more than 3,000 volcanoes in Chilean Andes are said to be active. Nevados Ojos del Salado on the Argentine-Chilean border is the world's highest active volcano, last reported to have spewed lava about 1,000 years ago, though details of the event remain sketchy.