The cloud of ash spewing from a volcano in Chile grounded more flights Tuesday in South America, forcing Peru's president-elect to cross a river by boat and threatening to delay the start of the continent's football championship.

The schedule of next month's Copa America could be altered if the ash cloud from Chile's volcano keeps grounding flights, Argentine Football Association President Julio Grondona said.

"We're watching it closely and it's for sure that teams are not ready to come to Buenos Aires," Grondona told Argentine broadcaster Radio 10. "The tournament starts July 1 and we hope that within five or six days the problems with the ash will not exist."

Peruvian President-elect Ollanta Humala, who met with Argentine President Cristina Fernandez on Tuesday, was forced to take a boat across the Rio de la Plata from Montevideo, Uruguay, to Buenos Aires on Monday because flights were grounded.

The main international airports in Argentina and Uruguay were closed because of ash from Chile's Cordon Caulle volcano, while across the Pacific flights resumed over Australia's mainland as the ash drifted.

The cloud of fine grit can damage airplane engines and it had disrupted hundreds of flights since the volcano began erupting June 4. In areas near the volcano in Chile, about 4,000 people have been evacuated from their homes.

Hundreds of passengers were stuck in terminals as flights remained grounded at Buenos Aires' main airports.

Many of those forced to change their travel plans have been tourists, and resorts in the mountains of Patagonia that have been blanketed with ash say they expect major losses due to the dearth of visitors.

Organizers of the Copa America weren't the only ones worried about the possible affects on a football tournament. Organizers of the club-level Copa Libertadores had talked of delaying Wednesday's match in Uruguay between Brazil's Santos and Uruguay's Penarol due the lack of flights, but the Brazilians managed to arrive Tuesday.

All Australian mainland flights resumed Wednesday after ash moved out to sea, but most airlines suspended service to Tasmania and New Zealand for a fourth day.

New Zealand's Civil Aviation Authority said the ash will be back in Chile soon, after circling the globe. Even if the eruption were to stop now, however, the agency said Australia and New Zealand can expect at least another week of ash clouds.

In Chile, ash stopped falling Tuesday on some small towns near the volcano after leaving a thin film on homes, the governor's office said in Ranco, a province located about 500 miles (800 kilometers) south of Santiago.

Although seismic activity has lessened, experts have been closely monitoring the eruption while the volcano has been shrouded intermittently by clouds and rain.

In Ranco, authorities on Monday allowed dozens to return to their homes and the provincial government said others returned temporarily to tend to their cattle and other farm animals.

Last week, steaming rivers near the volcano were filled with tons of hot volcanic rocks, and experts said the temperature of the Nilahue River reached 113 degrees Fahrenheit (45 degrees Celsius), killing off large numbers of salmon.

The Nilahue River has now cooled to its normal temperature of about 42 degrees Fahrenheit (6 degrees Celsius), the Ranco government said. The river, which has been swollen with rainwater in recent days, has deposited large amounts of volcanic rock in Ranco Lake.

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Associated Press writers Debora Rey in Buenos Aires, Federico Quilodran in Santiago, Chile, Sarah DiLorenzo in Sydney, and Ray Lilley in Wellington, New Zealand, contributed to this report.