The violence erupted on Saturday when armed men in five 4WD vehicles crossed into Anbar province about 10 kilometers (six miles) from the al-Waleed border crossing with Syria, the Iraqi border police said.

Sources with the border police also said two gunmen were killed in the incident.

The conflict in Syria has spilled over into neighboring countries including Iraq on many occasions.

In one of the deadliest of such incidents, militants fighting the Syrian government ambushed a Syrian army convoy on the Iraqi soil in March.

The soldiers had entered Iraq for medical treatment and were on their way back to their home when they came under attack.

That attack left 48 Syrians and nine Iraqi guards dead.

The conflict in Syria started in March 2011, when pro-reform protests turned into a massive insurgency following the intervention of Western and regional states.

The unrest, which took in terrorist groups from across Europe, the Middle East and North Africa, has transpired as one of the bloodiest conflicts in recent history.

As the foreign-backed insurgency in Syria continues without an end in sight, the US government has boosted its political and military support to Takfiri extremists.

Washington has remained indifferent about warnings by Russia and other world powers about the consequences of arming militant groups.

NTJ/SHI