Five Iraqi judges escaped assassination Monday in a series of small bomb attacks that police believe may be part of a Shi'te extremist campaign to force them to free jailed militants or reduce their sentences. Only one of the jurists was injured in the attacks, which happened four days after senior judge Kamil al-Showaili of the country's Higher Judicial Council was assassinated while driving home in mostly Shi'te east Baghdad. Police said it was unclear whether al-Showaili's slaying was related to the latest attacks. However, it appeared all the incidents could be part of a campaign against a judicial system that US authorities have worked hard to reinforce after the collapse of Saddam Hussein's regime in 2003. Police said the top judge in the Shi'te district of Sadr City, Ghanim Abdullah al-Quraishi, was injured along with his wife and daughter when a bomb exploded near their car in a parking lot in northeast Baghdad. Small bombs also exploded near the homes or vehicles of three other judges, police said. A bomb was found at the home of a fourth judge but was disarmed, police said. Two officials of the Interior Ministry said they believed Shi'te extremists were responsible because all five judges have recently heard cases involving militiamen who had been sentenced to death or long terms in prison. Both officials spoke on condition of anonymity because they were not supposed to discuss the attacks with the media. The threats against the judges occurred at the end of a month which saw a slight uptick in violent incidents - although still far below levels of 2006 and early 2007. At least 29 American soldiers died in Iraq in June, compared with 19 the previous month - the lowest monthly figure of the war. At least 546 Iraqis were killed or found dead this month in war-related violence, according to figures compiled by The Associated Press as of Sunday. That was a slight increase over the May figure of 515, according to the AP. In the latest violence, a car bomb exploded Monday evening in the northern city of Mosul, missing an Iraqi army patrol but killing one bystander and wounding 12 others, police said. The US military said American soldiers killed six al-Qaida militants in two separate incidents the day before near Balad, 50 miles north of Baghdad. The statement also said US forces detained 22 al-Qaida suspects on Sunday and Monday in several other areas of Iraq.