Updated

Dynamite (search) used for building a water channel blew up in a northern Pakistani village early Sunday, killing at least 45 people and injuring 150 others.

It exploded when the house it was being stored in caught fire, apparently because of an electrical short circuit, police said. They said the house belonged to a local contractor who died in the blast in Ghair, 180 miles east of Gilgit (search).

Construction crews frequently use explosives to clear land for roads and other projects in the mountainous area -- home to K-2 (search), the world's second-tallest peak. The government is trying spur economic growth in the poor region and make it more accessible to tourists.

Villager Ghulam Sakhi told The Associated Press by phone that the wood house caught fire about midnight, and that more than 200 neighbors, including women and children, rushed to help extinguish the blaze.

"But the flames reached a big room where explosives were stored, triggering blasts," Sakhi said.

Many of the 45 killed were women and children, and rescue crews were digging through debris searching for more bodies, police said.

The blast damaged more than a dozen houses and at least 13 people were missing, said Brig. Javed Iqbal Cheema, director general of the National Crisis Management Cell in the Interior Ministry.

He said about 150 people were taken to hospitals. One doctor, Bahadur Khan, said patients described seeing a "huge ball of fire," and that one injured villager said he saw dozens of "burning bodies flying in the air."

President Gen. Pervez Musharraf sent a message to the victims' families and ordered an inquiry into the explosion, the state-run Associated Press of Pakistan reported.

So far, investigators only know the contractor planned to use the explosives to clear rocks for a government-funded water channel, Cheema said.

Many Pakistani companies do not have proper storage facilities for explosives. A blast at a fireworks plant last month killed a woman and her two children in the eastern city of Lahore. Police suspected that a record-breaking heat wave sparked the explosion.