Turkish army says Kurdish militants attack convoy ISTANBUL (Reuters) - Turkey's military said Kurdish militants attacked a convoy of military vehicles with rifles and a rocket-propelled grenade in southeast Turkey on Friday. There were no casualties, but it appeared to be one of the most serious breaches yet of an 8-month-old ceasefire between the government and PKK militants. The rebels previously opened fire on a military helicopter in June and an army outpost the following month. The general staff said the attack occurred near the border with Syria, where thousands of Kurds protested last week against the building of a border wall. "Members of the separatist terrorist group set up an ambush and fired 100-150 rounds of ammunition," the military statement said, using the term it generally uses to describe the PKK or Kurdistan Workers Party. It said the guerrillas also fired an RPG-7 rocket, which missed an armored vehicle at the back of the convoy. Soldiers in the convoy fired back and the shooting then stopped. There was no immediate comment from the PKK. Its jailed leader Abdullah Ocalan began talks with Turkish officials last year to halt a conflict that has left more than 40,000 people dead over the past three decades. He ordered his fighters in March to cease fire. But in an interview with Reuters last month, a senior PKK leader in northern Iraq said the rebels were ready to re-enter Turkey after many withdrew over the summer, threatening to rekindle their insurgency unless Ankara resuscitates their peace process soon. The PKK is designated a terrorist organization by Turkey, the United States and the European Union. Writing by Daren Butler; Editing by Mark Trevelyan