BAGHDAD - Iraqi army and police commanders leading an ongoing battle for control of the country's biggest refinery say they cannot defeat Islamic State unless they change tactics to better cope with the insurgents' guerrilla warfare techniques.
The sprawling refinery complex near the town of Baiji north of Baghdad has changed hands several times over many months of fighting, one of the main fronts in Iraq's bid to recapture the third of its territory held by the Sunni Muslim insurgents.
The Iraqi government has had mixed fortunes since a US-led alliance joined the campaign against Islamic State last year by bombing positions in both Iraq and Syria where Islamic State has proclaimed a caliphate to rule over all Muslims.
In March, the army and its Shi'ite militia allies recaptured former dictator Saddam Hussein's home town Tikrit in the Tigris river valley north of Baghdad. But the fighters responded with their own major victory last month, capturing the city of Ramadi in the valley of Iraq's other great river, the Euphrates.
Baiji, just north of Tikrit, is an important test of whether the government forces can reclaim momentum. But they have so far failed to secure victory there against a mobile and hidden enemy that has proven expert in unconventional tactics.
"They are professionals in guerilla warfare, contrary to our forces which follow an old fighting style," said Brigadier General Nasir al-Fartousi, commander of the interior ministry rapid intervention division tasked with retaking Baiji.