BAGHDAD (AP) — Iraq's most influential Shiite cleric appealed to Iraqi politicians on Friday not to make themselves "an obstacle" in the country's transition as the deadline looms for selecting the next prime minister. The next government is expected to grapple with an unprecedented blitz offensive by Sunni extremists from the Islamic State group, which in June seized a large chunk of the country's north and west. Militants with the Islamic State have also destroyed ancient shrines and mosques in Iraq's second-largest city, Mosul, claiming they stray from hardline Islamic practices and instead promote apostasy. To the north, Ninevah and Salahuddin have seen heightened violence since militants seized parts of both provinces, including the provincial capitals of Mosul and Tikrit. In Haditha, a town in Anbar near a strategic dam, fighters with the Islamic State group launched a three-prong assault on Friday, using a suicide oil tanker and trucks, Lt.