Rubble in the streets of central Kirkuk, Iraq.<br/> <br />Three roadside bombs exploded here on Sunday, near a Shi'ite mosque.<br/> <br />A car bomb and a roadside bomb were detonated elsewhere near a Kirkuk television station.<br/> <br />And bombs planted in a car in the city of Jalawla killed two Kurdish military recruits just hours earlier.<br/> <br />The blasts killed at least nine people and injured 30.<br/> <br />The carnage comes at a time of escalating tension between Baghdad and the autonomous Kurdistan region in the north<br/> <br />Friction is growing after both regions sent troops to reinforce positions along the contested internal frontier.<br/> <br />Although Kirkuk sits outside the three northern provinces administered by Kurdistan, ethnic Kurds lay historical claim to the city and say it should be part of the Kurdish region.<br/> <br />Kurdistan has run its own government and armed forces since 1991.<br/> <br />But the Kurdish region has increasingly clashed with Baghdad by signing oil agreements with companies like Exxon Mobil-- deals the central government dismisses as illegal.