BAGHDAD  Two insurgent bomb blasts struck Thursday at pro-American Iraqi targets in Anbar Province just west of Baghdad and in the northern city of Mosul. The police said more than 30 Iraqis were killed and 80 wounded.

An American military spokesman and Iraqi police officials said that three American marines were killed in the Anbar attack and that two interpreters were also among the dead. The American military command was preparing to hand control of the province, once considered the hotbed of the insurgency, to Iraqi forces.

The bombings extended a pattern of multiple-casualty attacks in recent days that are clearly intended to kill local Iraqi leaders, in particular those who are believed to have collaborated with American forces against insurgents. Thursday’s attacks were among a string of deadly episodes in the past week that broke the previous several weeks’ lull in violence.

Most of the episodes have occurred in Sunni or mixed Sunni-Shiite areas where there has been mounting frustration over the lack of a political deal giving power to all of Iraq’s factions. Some were in small neighborhoods like Abu Dshir on the southern edge of Baghdad, and Madaen, which lies just to its southeast. There was also an attack on Tuesday on the Sadr City neighborhood council which killed six Iraqis, four Americans and an Iraqi-Italian interpreter.