Tropical storm Agatha has left 12 people dead and 11 missing in Guatemala, and forced the evacuation of about 3,000, officials said Saturday.

Two adults and two children were killed when a boulder dislodged by the rains crushed their home in Alomolonga, in Quetzaltenango province, about 200 km west of the capital, emergency officials said.

An additional 11 people were reported missing as Agatha, the first storm of the current Pacific hurricane season, picked up momentum and heavy rains flooded three rivers in the west part of the country.

Guatemala has declared a state of emergency as the storm moved closer with a maximum sustained wind speed of 75 km per hour. President Alvaro Colom said the government would seek 85 million dollars in loan for relief to storm victims and those affected by the ongoing eruption of volcano Pacaya.

"The worst will come around 9 a.m. (Sunday) and we are extending the state of emergency to the entire country," Colom said.

Agatha is expected to arrive in Guatemala Sunday and gradually weaken as it moves inland, but the rains would continue to fall through Tuesday, said Eddy Sanchez, head of the Meteorological and Seismology Institue.