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The Turkish government blamed a Kurdish rebel group Wednesday for a bomb attack that killed nine people near the Syrian border, amid concerns by ruling party officials that the militants may be developing links with the regime in Syria, and its civil war could have a destabilizing effect on Turkey.

The explosion in the southern city of Gaziantep on Monday followed an escalation in fighting between Turkish forces and the rebel Kurdistan Workers' Party, or PKK, which had close ties in the 1990s to then Syrian President Hafez Assad — current leader Bashar Assad's father. Turkey, which seeks the ouster of Assad, is sheltering nearly 70,000 Syrian refugees and has urged the United Nations to set up camps inside Syria for the displaced, a step that would require the intervention of a security force and pose a direct challenge to Syrian authorities.

Some commentators, however, have warned that Turkey misjudged the resilience of the Assad regime and is being pulled into a wider conflict with implications for the most vexing issue on its domestic agenda — a resolution of the state's conflict with Turkish Kurds who want self-rule in the mostly Kurdish southeast part of the country. The PKK has denied involvement in the Gaziantep blast, which numbered several children among the dead on a Muslim holiday, but Turkish officials, including President Abdullah Gul, cited the group's hand in similar attacks as a sign that it was the likely perpetrator.

"The incident is totally the work of the PKK," said Gaziantep governor Erdal Ata. "Certain information has been attained. It may not be right to share it now, but evidence is being assessed."

Anadolu, Turkey's state-run news agency, said anti-terrorism police detained four suspects in the neighboring province of Sanliurfa on Tuesday. They were taken to Gaziantep for questioning.

The threat of spillover from the Syrian conflict and its sectarian undertones has already been seen in Lebanon, the scene of clashes between supporters and opponents of Assad. It now appears Syrian Kurds are taking advantage of the chaos to take steps toward autonomy. Turkey fears the PKK, which includes many Kurds of Syrian origin, is also moving into the power vacuum there, possibly with the cooperation of regime elements who want to blunt Turkish efforts to dislodge them.

Foreign Minister Ahmet Davutoglu said any alleged link between the PKK and the Syrian regime in the Gaziantep bombing would be investigated, while Huseyin Celik, deputy chairman of Turkey's ruling party, said there were connections between Kurdish rebels and Syrian intelligence.

"The PKK is an organization that is capable of carrying out such an attack on its own, but could it have had supporters in such an attack? It's possible," he said in an interview with Hurriyet newspaper that was published Tuesday. "After all, Assad, acting on the premise that 'the enemy of my enemy is my friend,' is in a tendency to regard Turkey's enemy, the PKK, as its friend. We don't have full information yet, but even if it is a guess, such a link is a probability."

Relations between Turkey and Iran, a supporter of Assad, are strained because they back opposing sides in Syria's civil war. Iran, which also has a Kurdish minority, has fought the Iranian wing of the PKK and in that sense shared a common fight with Turkey, a NATO member that has often conducted air strikes against militant camps in northern Iraq.

But Iran fiercely opposes Turkish backing for the Syrian political opposition and army defectors who organize from the safety of Turkish camps along the Syrian border. A short commentary on Iranian state television earlier this week hinted at a possible link between the Syrian conflict and the blast in Gaziantep, which lies 130 kilometers (80 miles) north of the Syrian city of Aleppo, where regime forces and the rebel Free Syrian Army are battling for control.

"The site of the explosion is close to the Syrian border and Aleppo," the commentary said. "It seems that Syria's trouble is going to sink Turkey, which supported Syria's turmoil, actively."

A Kurdish political party in Turkey that has been accused of acting as a political front for the PKK also criticized the Turkish government's involvement in the Syrian conflict, saying in a statement Tuesday that it was dragging the country "toward this perilous tide in the Middle East" at the expense of efforts to secure a domestic peace. On Tuesday night, the Gaziantep office of the Kurdish party, Peace and Democracy, was attacked by demonstrators who blamed Kurdish rebels for the bombing. The building's sign and windows were broken before security forces dispersed the crowd.

The government has launched economic initiatives and granted more cultural rights to Kurds while maintaining, along with its Western allies, that the PKK is a terrorist organization. Many in the Kurdish minority, who make up about 20 percent of Turkey's 75 million people, say their grievances have not been fully addressed and that their leaders are vulnerable to prosecution.

In another twist to the long Kurdish conflict, a bus carrying soldiers plunged down an embankment in southeast Turkey on Tuesday, killing 10 people, including nine servicemen. Turkish media said the soldiers were to provide security for a Kurdish politician who planned to visit some of the families of 34 villagers who were mistaken for Kurdish rebels and killed in an air strike in late 2011.

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Associated Press writer Suzan Fraser contributed from Ankara, Turkey.