Three Turkish soldiers were killed and six others injured by a mine explosion in south-east Turkey, news agency Anadolu reported Thursday evening, according to dpa. The mine was reportedly set off remotely by members of the Kurdish Workers' Party (PKK) as the soldiers' vehicle was travelling a highway in the Siirt province, Anadolu said. The incident is the latest in a series of attacks by PKK guerrillas in east and south-east Turkey and comes as the country warned that it has the right to launch a cross-border operation into northern Iraq to destroy PKK camps. An operation is complicated however, as the United States opposes an incursion fearing that it may destabilize the relative calm that exists in Kurdish-controlled northern Iraq. Eight soldiers were killed and six others injured in a PKK attack on Monday. The military believes there are around 5,000 PKK guerrillas based in camps in northern Iraq from where they slip across the border into Turkey. More than 32,000 people, mainly Kurdish civilians caught in the crossfire, have been killed since the PKK launched its fight for independence or autonomy in the early 1980s for the predominantly Kurdish-populated south-east.