Published: May 31, 2010 11:04 AM EDT
Updated: May 31, 2010 8:04 AM EDT

A blanket of volcanic ash has closed Guatemala's international airport.

The ash came from the nearby Pacaya volcano which began erupting on Thursday, killing at least one person.

Thousands of passengers were stranded as workers tried to clear the runway of ash.

That task became more difficult as rains from Tropical Storm Agatha began mixing with the falling ash.

The ash posed a serious threat to airplane engines, as Guatemala's president explained:

The volcano, which is 40 kilometres south of Guatemala City, sent plumes of ash almost 1,500 meters above its peak.

Authorities declared a state of emergency for the surrounding area, evacuating more than 1,600 people.

Scientists said this eruption was the volcano's strongest in decades.

Pacaya has been continuously active since the 1960's, but not since 1998 has it showered down rocks and ash.