US and Iraqi forces detained a suspect linked to networks bringing sophisticated roadside bombs into Iraq during a raid Friday in the main Shiite district in Baghdad. The suspect, who was detained by US and Iraqi forces during a raid in the Shiite militia stronghold of Sadr City, was believed to be tied to networks bringing the weapons known as explosively formed projectiles, or EFPs, into Iraq, the military said. It did not name the suspect or the groups he was accused of having ties to, but the US military has asserted in recent months that Iran's Revolutionary Guards and Quds force have been providing Shiite militias with weapons and parts for sophisticated armor-piercing bombs. The EFPs are responsible for the deaths of more than 170 American and coalition soldiers since mid-2004, the military says. Shiites elsewhere in the capital loaded wooden coffins into vans and shoveled broken glass and other debris into wheelbarrows in the aftermath of a double suicide bombing against a marketplace. That attack occurred about two hours after three suicide car bombers struck a market in Khalis, a mainly Shiite town north of the capital. The carnage in Khalis and the Shaab neighborhood in Baghdad killed at least 125 people and wounded more than 150 in one of Iraq's deadliest days in years. In all, at least 181 people were killed or found dead on Thursday as Sunni insurgents apparently step up their campaign of bombings to derail a US-Iraqi security sweep in its seventh week. The US military also said a soldier was killed and another was wounded Thursday during a patrol in southern Baghdad, raising to at least 3,245 members of the US military who have died since the Iraq war started in March 2003, according to an Associated Press count. The deadliest bombing on Thursday was in Shaab, a predominantly Shiite neighborhood in northeastern Baghdad, where two suicide attackers wearing explosives vests blew themselves up in the Shalal market, which was crowded with shoppers seeking provisions on the eve of the Muslim day of rest and prayer. At least 82 people were killed and 102 were wounded, police and hospital officials said. The Imam Ali hospital in nearby Sadr City was packed with the wounded on Friday, with two children lying in one bed, according to AP Television News footage. The Shaab neighborhood was one of the first that US and Iraqi forces tackled when the security crackdown for which US President George W. Bush has committed nearly 30,000 additional troops to dampen what had become uncontrollable violence in the capital. It also was the scene of a bombing nearly two weeks ago in which officials said a car bomber used children as decoys to get near the busy complex of shops and street vendors. Prime Minister Nouri al-Maliki, whose backing is dropping even among fellow Shiites, issued an angry statement pledging to bring bombers and their backers to justice. "We call on you (Iraqis) not to allow the evil ones to triumph and to cooperate with your armed forces. ... Justice will reach them sooner or later," he said. Violence has increasingly erupted in towns and cities outside the capital in recent weeks, as insurgent fighters take their fight to regions where US and Iraqi forces are thinly deployed. The US military and its diplomats have voiced cautious optimism about the sweep that began Feb. 14 and emphasized that the full American surge force would not be in place until June. Three suicide vehicle bombs, including an explosives-packed ambulance, detonated in a market in Khalis, 80 kilometers north of the capital, which was especially crowded because government flour rations had just arrived for the first time in six months, television stations reported. At least 43 people were killed and 86 wounded, police said. On Wednesday, Shiite militants and police went on a shooting rampage against Sunnis in the far northwestern city of Tal Afar, killing as many as 70 men execution-style. The killings were triggered by twin truck bombings there the previous day that killed 80 people and wounded 185. The Islamic State in Iraq, an umbrella group of insurgent and terror groups - including al-Qaida - claimed responsibility for the Tal Afar bombing attack in an Internet statement. Provincial police chief Brig. Abdul-Karim al-Jibouri said 18 policemen suspected in the case were back in custody, a day after local authorities said they had been released. New US Ambassador Ryan Crocker, meanwhile, presented his credentials to Iraqi Foreign Minister Hoshyar Zebari. In the meeting, Zebari reiterated his stance that 15 British sailors and marines recently detained by Iran were "captured inside Iraqi territorial waters and were working in Iraq as part of the multinational force at the request of the Iraqi government." Zebari, who called for the release of the British forces earlier this week, also said the Iraqi government was in contact with Iran to "ensure the wise handling of the case." The capture and detention of the British service personnel has put Iraq in a difficult position as it tries to secure Baghdad with the help of US-led coalition forces while maintaining ties with its neighbors, including US rivals Iran and Syria. The Iraqi government called on the sides to keep the tensions from spilling over its border after the US detained five Iranians in January in northern Iraq, accusing them of being part of an Iranian Revolutionary Guard force that provides funds, weapons and training to Shiite militias in Iraq. Tehran had insisted that the five detained Iranians were engaged exclusively in consular work.