The attack happened at sundown yesterday as the troops were marking the end of the first day of fasting during the Muslim holy month of Ramadan. It was the latest in a string of brazen strikes by militants that has killed more than 2,000 people since the start of April.
Gunmen launched their assault on an army checkpoint near the town of Barwana, which lies across the Euphrates River from the town of Haditha, about 220 kilometres (140 miles) northwest of Baghdad, according to Barwana's mayor, Meyasser Abdul-Mohsin.
Abdul-Mohsin said three soldiers died at the checkpoint and 11 troops at the trailer.
A security official in nearby Haditha gave a similar account and confirmed the death toll. He spoke on condition of anonymity because he was not authorised to release the information.
There was no immediate claim of responsibility. Sunni militants, including al-Qaeda's Iraq arm, frequently target security forces and the country's vital oil infrastructure in an effort to undermine the Shiite-led government.