MOUNT MERAPI, Indonesia -- Trains, buses and rented autos were crammed with Indonesians leaving a bustling, ash-choked city of 400,000 at the foot of Mount Merapi, which roared again Monday with explosions of volcanic gas and debris.
Authorities put Yogyakarta on high alert but haven't ordered evacuations of the university town some 20 miles (30 kilometers) from the peak. Many residents are leaving on their own, and neighborhoods on the edge of the city looked like ghost towns, houses shuttered, some with laundry still hanging outside.
"What choice do we have?" asked Sukirno, 37, as he sped away with his wife and their 8-year-old daughter on a motorbike, saying they would join relatives far away over fears the ash would harm their health.
The city's airport was closed yet again Monday, adding to the crowds at train and bus stations, and ash hung so thickly in the air that breathing was painful and clothes stunk of smoke after any time outdoors.
"My parents have been calling ... saying 'You have to get out of there! You have to come home!"' said Linda Ervana, a 21-year-old history student who was waiting with friends at a train station in Yogyakarta.
After days of failing to get tickets -- long lines stretch all the way through the main hall, some people sleeping on their luggage -- they decided to rent a minibus with other classmates.
"It feels like that movie '2012,"' said her 22-year-old friend, Paulina Setin. "Like a disaster in a movie."
One of the world's most active volcanoes, Merapi has erupted many times in the last century, killing more than 1,400. It revived two weeks ago and a significant eruption Friday launched hot ash and pyroclastic flows down the mountain slopes that claimed nearly 100 lives, its deadliest blast in 80 years.
Concerns about airborne ash after Friday's eruption prompted many international airlines to cancel flights to the capital, Jakarta, but all were flying again Monday. White House officials said President Barack Obama still was scheduled to arrive Tuesday in Indonesia -- his second stop in a 10-day Asian tour.
On Monday, Merapi shot clouds of gas and debris up to 3,000 feet (1 kilometer) in the air as ash and pyroclastic flows poured down its slopes. Scientists worry the series of eruptions hasn't eased pressure inside the volcano and instead proves Merapi is unpredictable.
"Based on what we're seeing now, it could erupt again any time," said Surono, a state volcanologist.
The overall toll since the eruptions started Oct. 26 climbed from 138 to 141 after more bodies were found on the mountain, the National Disaster Management Agency said.
Authorities have cleared people from a danger zone that is now 12 miles (19 kilometers) from the peak and are preventing them from returning. Nearly 280,000 people have jammed into emergency shelters they say lack enough toilets or clean drinking water.
Experts say the biggest threat to Yogyakarta isn't from the sky but rather the Code River, which flows into the city's heart from the 9,700-foot (3,000-meter) mountain. The river could act as a conduit for deadly volcanic mudflows that form in heavy rains, racing at speeds of up to 60 mph (100 kph).
Black volcanic sludge has already inundated one city neighborhood that slopes up a hill just above the river. In Romomangun, the mud burst the riverbanks and poured into buildings.
Indonesia, a vast archipelago of 235 million people, is prone to earthquakes and volcanoes because it sits along the Pacific "Ring of Fire," a horseshoe-shaped string of faults that lines the Pacific Ocean.
Associated Press writer Niniek Karmini in Jakarta contributed to this report.