A senior Iraqi official warned Sunday that the escalating anti-American insurgency may delay work on the country's new constitution, slowing steps toward the U.S. administration's goal of a democratic government here.

The U.S. command Sunday announced the death of another soldier, who was killed late Saturday when his vehicle struck a land mine in Baghdad (search).

Three paratroopers (search) from the 82nd Airborne Division (searchwere wounded in Fallujah, the military also reported. Witnesses said a British soldier was wounded Sunday by a land mine in the southern city of Basra (search).

Following the attacks in Fallujah (search), U.S. F-16 jets dropped three 500-pound bombs in the area late Saturday as part of an apparent new tactic of meeting armed resistance with massive shows of force.

"We are on offensive operations," a U.S. officer said on condition of anonymity. "You can expect to see an increase in the level of intensity and the amount of activity that is occurring, especially in those `challenging' areas."

Iraq's Foreign Minister Hoshyar Zebari (searchtold reporters he expected the interim Iraqi government to meet a U.N. Security Council deadline of Dec. 15 for submitting a timetable for a new Iraqi constitution and national elections.

"However, those timetables depend on the security situation, and if the security deteriorates, we will not be able to adhere to such commitments," Zebari said after a meeting with Spanish Foreign Minister Ana Palacio.

A new constitution would enable Iraqis to govern themselves and hasten the day when American and other coalition forces could leave the country in the hands of a stable and democratically elected administration.

The United States and its coalition partners consider adoption of the new constitution and national elections as key steps in the reestablishment of a sovereign Iraq.

However, the U.S.-appointed Iraqi Governing Council has not decided how to chose the delegates to a constitutional convention that will write the document. Leaders of the majority Shiite Muslim community want the delegates chosen in a national election, something U.S. officials believe would take too long.

Other proposals have included the Governing Council selecting delegates from a list of nominees submitted by regional and local leaders.

Attacks against coalition forces picked up since last month, reversing a steady decline during the summer. Nearly half of the 150 American soldiers killed by hostile fire since President Bush declared an end to active combat in Iraq on May 1 have taken place in the past five weeks.

In Mosul, a senior U.S. commander blamed the attacks in his sector on a "marriage of convenience" between members of the former regime, criminals and foreign fighters.

"There are former regime members who want to disrupt the successes achieved here in the north," Maj. Gen. David Petraeus, commander of the 101st Airborne Division, said. There are also "criminals ... who are willing to be guns for hire," as well as "some foreigners who have come in small numbers and have been involved in this as well."

On Saturday, Deputy Secretary of State Richard Armitage said the U.S. administration had been "sobered" by the escalation of violence but maintained that "we have a very solid plan to go out and get these people who are killing us and killing Iraqis."

As an example, U.S. officials said Sunday that 18 people had been arrested in connection with last month's fatal missile barrage against Baghdad's Al-Rasheed hotel in which one U.S. colonel was killed and 18 people wounded.

In Tikrit, a U.S. official said Sunday that an American major general was aboard a military helicopter that flew with the Black Hawk that crashed there last week, killing six soldiers. The Black Hawk was apparently shot down by insurgents.

The helicopter carrying the general, whom the military refused to identify, landed safely, according to Maj. Josslyn Aberle, spokeswoman of the 4th Infantry Division.

The Black Hawk helicopter, however, burst into flames Friday and plummeted into a grassy field on the eastern bank of the Tigris River, military officials said, citing witnesses. Two of the dead were from the Department of the Army headquarters at the Pentagon, the military said.

Following the Friday crash, U.S. forces reimposed an 11 p.m.-to 4 a.m. curfew in Tikrit and launched a crackdown, intensifying patrols and searches and blasting at least two houses and a warehouse believed to have been used by anti-U.S. insurgents.