As Turkey dreams of joining the wealthy European Union, and gears up for the summer tourist influx that feeds its economy, it is suffering a wave of bombings by an old adversary — Kurdish rebels.

This time the violence that used to be confined to outlying areas is hitting Istanbul, the largest city, and tourist resorts.

The eight bombings of the past three months, which left two dead and 47 injured, have been claimed by a group calling itself the Kurdistan Freedom Falcons. It is urging Turkish Kurds to bring "fear and chaos" to the country of 70 million and has posted bombing-making instructions on its Web site alongside praise for suicide bombers.

It claimed at least two bomb attacks at tourist resorts last year and is warning tourists to stay away.

The Falcons' emergence could signify a new phase in the decades-long war between Turkish troops and autonomy-seeking guerrillas who claim the 15 to 20 percent Kurdish minority has second-class status. That struggle was highlighted recently by the killing of 40 guerrillas and of 12 demonstrators in subsequent riots in the overwhelmingly Kurdish southeast.

"Come to duty now with the motto: 'revenge, revenge, revenge,'" the group's Web site told Kurdish youth.

"We will not recognize any rule. Everything and everywhere are targets for us," the Falcons added in warning off tourists. "From now on, our attacks will continue and become more violent."

The Falcons are a splinter group of the Kurdistan Workers Party, or PKK, the main militant group in southeastern Turkey. The PKK suffered a string of battle defeats and the 1999 capture of its leader, Abdullah Ocalan, apparently left his lieutenants divided over whether to keep fighting or pursue a political agenda.

The PKK called a unilateral cease-fire after Ocalan's arrest, but resumed fighting in 2004 because Turkey still rejected it as a terrorist organization and refused to talk to it. The United States and the European Union also regard the PKK as a terrorist group.

The Falcons, formed the same year, accuse the PKK of weakness and claim to be attracting disaffected PKK guerrillas to their ranks. Unlike the PKK, which has its base of support in southeastern Turkey, the Falcons appear to draw core support from Kurds who fled the 1990s fighting and took refuge in slums ringing Turkish cities.

The relationship between the PKK and the Falcons is not clear. Analysts note that the PKK in the past has been quick to suppress rival groups, and the Falcon's Web site pledges loyalty to Ocalan, the jailed PKK leader.

Nihat Ali Ozcan, an expert on the Kurdish rebellion, says the Falcons are a PKK product which is helping to keep the militants' cause alive as the PKK has weakened, and has ended the internal bickering by refocusing Kurdish strategy on fighting.

With the Falcons, "the PKK has added a new dimension to its fight on the mountains, staging terror attacks and provoking riots in major cities," Ozcan said. "This is a strategy to keep its cause alive by agitating young, unemployed and unhappy Kurds living in big metropolises."

The Falcons have a few hundred militants operating in small cells in western cities, said an anti-terrorism police officer, speaking on condition of anonymity. Turkish officials are not permitted to speak on the record without prior permission.

Besides detailed instructions on making bombs with fertilizer, clocks and radios, the Web site says: "Everywhere in Turkey, the bombs will explode, the assassinations and sabotage actions will take place."

The bombings come as the European Union presses Turkey to give the Kurds greater cultural rights as one of the criteria for admitting the country to the bloc. Turkey has recently allowed limited broadcasts in the once banned Kurdish language as well as private Kurdish language courses. But the militants dismiss the reforms as insufficient.