Iraqi Shia pilgrims pray in Kerbala. Roadside bombs targeting pilgrims near the city have killed four. Photograph: Nabil Mounzer/EPA A car bomb in a busy market in the southern Iraqi city of Diwaniya has killed at least 25 people and wounded 50 others, police and a provincial council official said, in the latest of a series of sectarian attacks. Earlier in the day, two roadside bombs targeting Shi'ite pilgrims killed four people and wounded 21 near the central Iraqi city of Kerbala, according to hospital and police sources. In Diwaniya, 125 miles (150km) south of Baghdad, police announced a partial curfew and closed all entrances to the city. The bombing took place near a Shi'ite mosque where pilgrims were gathering on their way to Kerbala to celebrate the birthday of one of the most important imams - al-Mahdi. Attacks have increased in Iraq in recent weeks, raising fears the country may slip back into widespread violence between Iraqi Sunni and Shi'ite muslims. Last month, at least 237 people were killed and 603 wounded, mainly in bomb attacks, according to a Reuters tally, making June one of the bloodiest months in Iraq since US troops withdrew at the end of last year. The deadliest attack occurred on 13 June when bombers targeting Shia pilgrims killed more than 70 people. Sunni insurgents have attacked Shia targets in a bid to repeat the violence that killed tens of thousands of people in 2006-2007. Iraq's al-Qaida wing has claimed responsibility for some of the recent bombings.