BAGHDAD, Jan. 2 (Xinhua) -- Iraqi security forces killed 15 Islamic State (IS) militants who were trying to infiltrate into Iraq from neighboring Syria, the Iraqi Interior Ministry said Tuesday.

Acting on intelligence reports, the federal police and the Iraqi intelligence Agency ambushed and killed 15 IS militants who were trying to move into Iraq through the Syrian border in western Iraq, Brig. Gen. Saad Maan, spokesman of the ministry, said in a statement.

The intelligence agency spotted the infiltrated terrorists, who were carrying weapons and explosive vests, and tracked them for several days before killing them, Maan said.

On Dec. 9, Iraqi Prime Minister Haider al-Abadi officially declared full liberation of Iraq from IS militants after Iraqi forces seized the entire border areas with Syria and the nearby desert in western Iraq.

However, individual IS militants are still trying to infiltrate into Iraq from neighboring Syria through the roughly 600-km-long border with vast rugged areas and desert land.