Iraqi-Kurd tensions soar after firefight Iraqi army spokesman Col. Dhia al-Wakil said the additional troops were dispatched "only as a precautionary measure, to face any possible attack from the pesh merga." But Kurds said they suspect that the reinforcements, which include tanks and heavy artillery, signal an intent to attack their forces. "If the central government keeps sending these extra troops, we fear there may be clashes," said Jabar Yawar, the pesh merga's secretary general. If one bullet is fired, the whole of the disputed areas will erupt in flames. American officials have stepped in to mediate amid concerns that a crisis that is rapidly becoming the worst since U.S. troops left almost a year ago could explode into full-blown war. Diplomats are in contact with leaders throughout Iraq "to emphasize the need to move quickly to alleviate current tensions," said an embassy spokesman, who spoke on the condition of anonymity because of the sensitivity of the situation. "It is important that all sides remain committed to resolving their differences through dialogue," the spokesman added. The escalation came after days of taut exchanges between Iraq's Prime Minister Nouri al-Maliki and Kurdish President Massoud Barzani in the wake of the firefight, which flared after two Arab men refused to pay a local vendor for gasoline. The vendor complained at an Iraqi police checkpoint, Kurdish guards at the nearby home of a Kurdish official accused the police of complicity, the Iraqi army showed up, "and everyone started shooting at everyone else," said Shalal Abdul, Tuz Khurmatu's Kurdish mayor. Guards at the offices of three local political parties, one Arab, one Kurdish and one from the Turkmen community, joined in the battle, in which 10 guards and police officers were injured and a passing tractor driver was killed. "It was a kind of chaos," Abdul said. It was personal, not political. But it has blown up beyond all proportion. Indeed, the speed with which a seemingly minor fracas spiraled into a full-fledged crisis underscores the dangers of the many unresolved disputes between Baghdad and Irbil, the capital of the Kurdish region. Their quarrels, over the distribution of land, money, power and oil, are not new, but they have intensified in the year since U.S. forces withdrew, taking with them the mechanisms and structures put in place during the final years of the Iraq war to avert such an escalation. A forlorn, windswept town of 50,000 straddling the highway linking Baghdad to the disputed city of Kirkuk, Tuz Khurmatu typifies the combustible mix of sects and ethnicities that characterize more than a dozen contested communities strung out along the country's Arab-Kurdish fault line, dubbed "the trigger line" for its potential to ignite conflict. U.S. troops had deployed along the line for the last two years of the war in an effort to forge an understanding between Iraqi and Kurdish forces that they hoped would outlast their presence. It appears it did not.