Three Diyala provincial officials were shot down Sunday by unknown assailants as they were on their way to a funeral for a fourth colleague killed earlier in the week, Iraqi officials said. Jassim Mohammed, a governor's aide for refugee affairs, was killed along with Diyala provincial council members, Shihab Ahmed and Dureid Mohammed, said Deputy Governor Ghassan al-Khadran. The three were attacked in the Mahmoudiya area, about 40 kilometers (25 miles) south of Baghdad, as they were headed to the holy city of Karbala for the burial of the mayor of the town of Hebheb, who was killed by gunmen on Thursday.