BAGHDAD: An Iraqi police official says the number of people killed in a suicide car bombing near a Shiite mosque in northern Iraq has climbed to at least 20. The official says the bomb exploded as worshippers were leaving a mosque after Friday prayers in Rasheediyah, north of Baghdad. The official says at least 45 people have been injured, and the toll is expected to rise. The police official spoke on condition of anonymity because he is not authorized to release the information to the media. It is the latest bombing in a series of attacks Friday to target Shiites. In Baghdad, three bombs killed seven people and injured dozens. The attacks have raised concerns that insurgents are hoping to re-ignite sectarian violence. Earlier, a series of bomb attacks targeting Shiite pilgrims and worshippers struck Iraq Friday, killing at least 17 people and wounding dozens more, police and medical officials said. The incidents are the latest in a series that have targeted Shiites, raising concerns that insurgents are stepping up attacks, hoping to re-ignite sectarian violence that nearly tore the country apart in 2006 and 2007. Though violence has dramatically declined in Iraq in the past two years, U.S. officials have repeatedly called the security gains fragile and cautioned that a waning insurgency still has the ability to pull off sporadic, high profile attacks. The most deadly blast occurred in Rasheediyah, a village north of Mosul, where a parked car bomb exploded near a Shiite mosque, killing at least 10 worshippers leaving Friday prayers, said a police official in Ninevah operations command. The official said dozens more were injured in the blast. In Baghdad, roadside bombs targeted Shiite pilgrims returning from the southern holy city of Karbala. The first of three bombs exploded at about 9:10 a.m., targeting a minibus with pilgrims as it entered the Shiite slum of Sadr City, a police official said. The blast killed four pilgrims and wounded eight others, the official said. The causalities were confirmed by a medical official. A short time later, two near simultaneous explosions near the Shaab football stadium in eastern Baghdad killed three pilgrims as they were walking home to Sadr City, said another police official. Thirteen pilgrims also were wounded in the two blasts, which occurred less than half a mile apart, the official said. All the officials spoke on condition of anonymity because they were not authorized to release information to the media. The blasts came a day after a roadside bomb targeted pilgrims on their way to Karbala, killing one and wounding four others. Last Friday, a string of bombings targeted Shiite worshippers in the Baghdad area during Friday prayers, killing at least 29 people. No group has claimed responsibility for the attacks. Attacks on Shiite civilians — particularly during pilgrimages — have been the hallmark of Sunni extremists, including al-Qaida in Iraq. Hundreds of thousands of devout Shiites have been traveling by foot or by vehicle to Karbala, 50 miles (80 kilometers) south of Baghdad, to celebrate the birth of Mohammed al-Mahdi, the 12th Shiite imam, who disappeared in the ninth century. Devout Shiites call him the Hidden Imam and believe he will return to restore peace and harmony. In 2007, the celebration, known as Shabaniyah, was tarnished when armed clashes broke out between followers of anti-American cleric Muqtada al-Sadr and security forces controlled by rival Shiite groups. Last year, suicide bombers targeted pilgrims, killing more than two dozen people. Iraqi forces have stepped up security on the road to and from Karbala. The ceremonies reached their high point Thursday and concluded early Friday morning. While overall attacks are down in Iraq, armed robberies targeting jewelry stores, currency exchanges and banks appear to be on the rise. Gunmen broke into a goldsmith shop in the western Baghdad district of Baiyaa on Thursday, killing the owner and making off with an unknown quantity of gold, two Iraqi police officials said Friday. One interior ministry official disputed the robbery, saying no gold was stolen and gunmen targeted the owner in a drive-by shooting. The officials spoke on condition of anonymity because they were not authorized to talk to the media. The robbery follows a bank heist last month in Baghdad where gunmen killed eight security guards and made off with millions of dollars. Iraqi authorities have said they arrested the nine gunmen and recovered all the money. Iraqi Vice President Adel Abdul-Mahdi said in a statement this week that one of those alleged gunmen served as one of his bodyguards and eight others were soldiers in the Iraqi army.