Baghdad: Turkey's military now has a green light to chase Kurdish guerrillas into northern Iraq but the approach of winter and fears of getting bogged down in mountainous terrain severely limit its options.

The Ankara parliament approved a motion on Wednesday giving Nato's second biggest army free rein to pursue Kurdistan Workers Party (PKK) fighters based in mainly Kurdish northern Iraq, which they use as a launchpad for attacks on Turkey.

"If they are going to do a major operation they don't have much time. We are talking weeks before weather conditions get bad. It has already begun snowing there," Gareth Jenkins, an Istanbul-based expert on Turkey's military, said.

The powerful army will want to avoid getting bogged down in a protracted fight against veteran guerrillas in difficult terrain the PKK has been in command of for several years.

NJ Gohel, director of the Asia Pacific Foundation, an independent security and intelligence think-tank, said that to be effective, the Turkish military would have to go at least 60km deep into northern Iraq.

"That would be dangerous as they would get sucked into a guerrilla war very quickly," he said. "The PKK units are very mobile. The Turks would be chasing an invisible enemy that blends in with the local population and has mountainous hideouts.

"Past experience has shown in Vietnam and Afghanistan, not to mention Iraq, that a conventional army is very ill-equipped to fight a guerrilla war," he said.

With the onset of winter, analysts say, Turkey's options will be reduced to air strikes and commando raids.