The U.S. military says a recent series of deadly bombings in Iraq does not signal a trend toward rising violence in the country.

U.S. military spokesman Rear Admiral Gregory Smith said Sunday in Baghdad that recent attacks should be compared with the situation a year ago.

Iraq's overall level of violence is down sharply from last June, when the U.S. deployed 30-thousand additional troops in the country.

But, attacks blamed on al-Qaida in Iraq have killed scores of people in recent weeks.

Two bombs exploded in a Baghdad shopping district on Thursday, killing 68 people. Last month, about 100 people died when two mentally-disabled women blew themselves up at pet markets in the Iraqi capital.

Senator Carl Levin, Senate Armed Services Committee Chair (File)

In violence today, Iraqi officials say a roadside bomb blast killed a policeman and wounded several others in the city of Tikrit.

In another development, two U.S. senators have asked U.S. government auditors to determine what Iraq is doing with the money it makes from selling oil.

Senators Carl Levin, a Democrat, and John Warner, a Republican, sent a letter Friday asking the U.S. Government Accountability Office to perform the audit.  The senators said they believe U.S. taxpayer money has paid for an overwhelming portion of Iraq's reconstruction despite billions of dollars of Iraqi oil revenue sitting in non-Iraqi banks.

The senators asked the auditors to examine how much oil money Iraq has made, and why the Iraqi government has not spent more on its own country.

A U.S. government report issued in January said violence in Iraq has reduced the number of contractors willing to bid on projects.

Some information for this report was provided by AFP and Reuters.