BAGHDAD, Iraq - A U.S. soldier died in a bomb blast north of Baghdad today amid warnings that attacks will likely increase with fewer than 100 days left before the coalition hands over sovereignty. A day earlier, a gunbattle with insurgents left one American soldier and three rebels dead.

A 1st Infantry Division soldier died and two were wounded when a homemade bomb exploded near Baqouba, the military said. The soldiers went to the area after Iraqi security notified them that a homemade bomb had been found. The two injured soldiers were in stable condition.

The gunbattle that killed one soldier occurred Wednesday near Taji, just north of the capital, said Brig. Gen. Mark Kimmitt, the U.S. military's deputy director of operations. A U.S. soldier was also wounded.

On Tuesday, guerrillas attacked a patrol in the town of Hamam al-Alil, 210 miles north of Baghdad, wounding a U.S. soldier, Kimmitt said. Troops returned fire and killed one attackers.

He said the military was worried by attacks on Iraqi police. On Wednesday, the police chief of southern Babil province was shot and killed. A day earlier, nine police recruits were killed in a nearby attack on their vehicle.

"We remain concerned at what is clearly a program of intimidation and targeting of not only the Iraqi police service, but all Iraqi government officials," Kimmitt said. "A significant number of Iraqi police have been killed in the past year, somewhere in the order of 350."

He said that despite the attacks "on almost a daily basis," morale in the force remained high and no significant drop in recruitment or retention rates had occurred.

With fewer than 100 days until U.S.-led occupiers transfer power to Iraqis on June 30, U.S. and Iraqi officials expect Iraqi guerrillas and foreign fighters to step up attacks in an attempt to disrupt the handover process and try to demonstrate that a fledgling Iraqi government cannot control the country.

"The security issue cannot be overemphasized," Mouwaffak al-Rubaie, a Shiite Muslim member of the U.S.-appointed Governing Council.

L. Paul Bremer, the top administrator in Iraq, said Wednesday that significant steps had been taken to rebuild the country since a U.S.-led invasion toppled Saddam Hussein a year ago.

"One hundred days from now, Iraqis will be sovereign in their own land and responsible for their own future," Bremer said in an outdoor speech in the Green Zone, the heavily protected area housing the coalition headquarters in the center of Baghdad.