BAGHDAD -- U.S. and Iraqi officials are seeing a shift in violence in Iraq from mass car bombings to assassinations using magnetic bombs, weapons with silencers and bicycle bombs.

As provincial elections approach, some officials worry that assassinations will increase as political parties try to eradicate their competitors.

"Some of the organizations that are seeking political power are resorting to intimidation and violence," said Maj. Gen. Michael L. Oates, commander of the Army's 10th Mountain Division, whose area of command includes most of southern Iraq. "So you'll see individual bombs used against a prominent member of a party. I personally think we will see an uptick of that type of violence as we go into the election cycle because ... the way some people deal with political tension here is to eliminate the other parties by using violence."

Yesterday, a prominent parliament member from the Shiite Muslim faction led by radical cleric Muqtada al-Sadr was killed near his home, when an explosive-laden motorcycle rammed his convoy. Saleh al-Ugaili died in a Baghdad hospital of his wounds.

A Karbala City Council member was killed by a magnetic bomb attached to his car. In Baghdad, another magnetic bomb killed a man as he drove through a busy shopping district.

The Ministry of Interior has issued a warning asking people not to park in public places to avoid militants' attaching magnetic bombs to vehicles. The weapons are then remotely detonated using a cell phone.

The lawmaker's death yesterday struck fear in other parliament members and drew strong condemnations from Iraqi Prime Minister Nouri al-Maliki, a Shiite; the Iraqi Islamic Party, a Sunni organization; and the top U.S. officials in Iraq.

"This heinous crime was not just an attack against Dr. al-Ugaili; it was an attack against Iraq's democratic institutions," said a joint statement from Gen. Raymond T. Odierno and Ambassador Ryan Crocker.

This month, Gen. Odierno acknowledged that he was seeing a shift in tactics. "What we're seeing is a change in tactics by both al-Qaida and the [Shiite] special groups, or the special rogue elements that have been trained in Iran. What you're seeing is they are conducting intimidation assassinations against [Iraqi] government officials," the U.S. commander in Iraq told USA Today.

U.S. military officials said they have seen as many as 200 such attacks this year. Although the bombs, which are relatively easy to make, have been used since 2005, the numbers were so low previously that they weren't tracked before this year, a military official said.

Although U.S. military officials have little or no information about the increasing use of silencers, the Iraqi Interior Ministry has seen a rise in their use against its employees, as well as others. In the last three weeks, eight ministry officials have been killed or wounded by men using weapons with silencers, said Brig. Gen. Abdel Kareem Khalaf, an Interior Ministry spokesman.

"I think the political process itself is the target. There are some ... who don't want the political process to go on, and are targeting the politicians," said Maysoon al-Damluji, a secular legislator who mourned her colleague's death yesterday.

In July and August, at least 10 people were assassinated each month, mostly in Baghdad, by gunmen using silencers, police said. Gen. Khalaf said the ministry has detained some 112 people suspected of using weapons with silencers. "We have noticed a shift from targeting of masses to targeting of specific persons," he said, adding that the rise in magnetic bombs -- known as "sticky" bombs -- could be a result of the anonymity they provide.

In the capital's New Baghdad district, men with silencers have killed as many as seven people in the past two months, residents say. All were prominent Iraqi officers or members of Mr. Sadr's movement, they say.