Armed men attacked a police guardpost outside the U.S. consulate in Istanbul on Wednesday. Turkish officials called it "a terrorist attack" and said three attackers and three policemen were killed.
A U.S. Embassy spokeswoman said there were no reports of casualties among American consulate employees, but could not confirm Turkish media reports of injuries and deaths.
"At about 11 a.m., at least one assailant opened fire on the Turkish police guardpost area near the main entrance to the consulate," the U.S. embassy spokeswoman said, speaking anonymously due to the sensitivity of the matter. "We're cooperating with the police and taking the appropriate measures."
"There is no doubt that this is a terrorist attack," Istanbul Gov. Muammer Guler said, adding that three policemen "were martyred" and three attackers were killed.
Two other people, a policeman and the driver of a towing vehicle, were also injured, he said.
Istanbul prosecutor Aykut Cengiz Engin said the attackers were armed with pistols and shotguns. Forensic teams were seen examining a shotgun on the ground.
The attack occurred right outside the high-walled consulate compound in Istinye district. Television footage showed four people lying on the ground at the foot of the consulate's wall before officials removed the bodies.
Yavuz Erkut Yuksel, a bystander, told CNN-Turk television the attackers emerged from a white vehicle and surprised the guard.
"One of them approached a policeman while hiding his gun and shot him in the head," Yuksel said.
Guler said two of the attackers were Turkish nationals, denying speculation that they were bearing Syrian passports. Police were pursuing a fourth attacker who reportedly escaped in a van.
The secure U.S. consulate building was built after homegrown Islamic militants linked to al-Qaida carried out suicide bombings in 2003 that targeted two synagogues, the British Consulate and a British bank in Istanbul. Those attacks killed 58 people.
The consulate occupies an imposing structure on a hill in Istinye, a densely residential neighborhood along the Bosporus Strait on the European side of Istanbul.
A reporter for The Associated Press who visited the consulate last week drove unimpeded past an entrance for the public and parked on a residential street two blocks away. The area directly in front of the entrance was kept clear of vehicles.
Several guards stood in separate locations outside the entrance, but weapons were not on display; Turkish civilians seeking visas and other documents sat at cafes across the street.
The choice of the city of Helsinki is not incidental as the capital of Finland had hosted US-Soviet negotiations on the limitation of nuclear stockpiles in 1969