Updated

A wildfire that leapt the Rio Grande (search) forced about 1,000 people -- including the mayor's family -- to temporarily evacuate their homes and prompted the governor to declare a state of emergency.

The blaze burned through 700 acres of brush along the river, causing a power outage that left 16,000 homes and businesses in the dark. Interstate 40, which crosses the river, was shut down for several hours.

"We are pretty sure it was caused by fireworks," Albuquerque (search) Fire Chief Robert Ortega said Wednesday.

Most of the evacuees were allowed to return Tuesday night, Ortega said. A house under construction was destroyed and another home was damaged.

The wildfire was one of many burning in Arizona and New Mexico. Firefighters in both states were hampered by hot, windy weather, low humidity and dry vegetation.

Firefighters were still mopping up spot fires in the Albuquerque area Wednesday, Ortega said.

Fire Department Lt. Lynn Reule said 50 firefighters were at the scene Wednesday morning, down from a peak of 140 Tuesday.

The fire burned along the west side of the Rio Grande (search), then jumped the river, at one point threatening an area of high-priced homes about two miles from downtown Albuquerque. Among those evacuated were the wife and children of Mayor Martin Chavez.

"You can see the flying embers, it's scary," said Liz Lardizabal, whose home is on the west side. "The whole street in front of our house is solid with fire trucks."

Lt. Gov. Diane Denish announced the state of emergency from the fire command center in Albuquerque. Gov. Bill Richardson and Chavez returned Tuesday from a visit to Mexico.

Meanwhile, Arizona officials upped the damage estimates from a wildfire that roared through the mountaintop hamlet of Summerhaven, near Tucson. They said 345 buildings were destroyed, more than the 250 originally feared.

The blaze, still burning on Mount Lemmon (search), had charred about 25,000 acres by Wednesday and was 25 percent contained. More than 1,200 firefighters and support personnel had been deployed to fight it.

Fire crews will likely complete the containment line surrounding the fire within three or four days, Buck Wickham, operations chief for the team battling the fire, said Tuesday.

The fire destroyed seven transmission towers and damaged six others. The financial costs of the damage haven't yet been estimated.