(Adds quote, PKK attack, background) By Thomas Grove ISTANBUL, Aug 7 (Reuters) - A mortar shell attack which injured three people in Istanbul on Thursday had targeted an army headquarters, broadcaster NTV reported security sources as saying. Unknown assailants fired four mortar shells from a cemetery and one crashed into a refuse vehicle by a municipal building near Selimiye Barracks, headquarters of the First Army, which guards the Bulgarian and Greek borders. Workers at a nearby municipal building, initially thought to have been the target of the attack, said they heard three explosions, state-run news agency Anatolian reported. The other three shells landed in the cemetery. It could not immediately be confirmed that the army headquarters were the target of the attack and security officials were still investigating. Police were searching for two people who escaped from the scene by motorcycle, Anatolian said. The attack comes at a time of heightened tensions in Turkey after a court last week fined the Islamist-rooted, ruling AK Party for anti-secular activities. It narrowly voted against closing the party. In the wake of the case, NATO-member Turkey hopes to put behind it a long power struggle between the AK Party and the powerful secularist establishment, including the military and the judiciary. In a separate ongoing court case, which has been seen by analysts as revenge for the closure case, retired military officers and others are accused of trying to trigger a coup against the governing party. PRIME MINISTER'S HOUSE Both court cases have hit Turkish markets, which have underperformed emerging market peers for most of this year. The target of the attack was initially thought to be a municipal building in Uskudar district, on the Asian side of Istanbul. Prime Minister Tayyip Erdogan represents a district on the Asian side of the city in parliament and has a house in Uskudar. Two bombs detonated in an Istanbul neighbourhood killed 17 people last week and six people were killed when three gunmen attacked the U.S. Istanbul consulate last month. Bomb attacks are common in Turkey, often carried out by leftists, Kurdish separatists and Islamic radicals. Military sources said Kurdish guerrillas launched a rocket attack on security headquarters in the eastern province of Mus overnight, killing one policeman and injuring three others. (Editing by Philippa Fletcher)
A Greenpeace balloon rises next to the towers housing Sabanci Holding, one of Turkey's biggest conglomerates, in Istanbul August 6, 2008. Greenpeace activists demonstrated in Istanbul on Wednesday to demand Sabanci ...
