The far-left Revolutionary People's Liberation Front (DHKP-C) has claimed responsibility for the attack on the US consulate in Istanbul.
The outlawed Marxist organisation said the attack was carried out by one of its female members.
On its website, the anti-US group identified the attacker as 51-year-old Hatice Asik who was later arrested and taken to hospital by the police.
"Our struggle will continue until imperialism and its collaborators leave our country and every parcel of our homeland is cleared of US bases," it said.
Turkish officials have also hinted that the attack was linked to the DHKP-C, which claimed the suicide attack on the American embassy in Ankara in 2013. Police forces have beefed up security outside the US and European consulates following the attack.
Ahmet Akçay,, a local resident who witnessed the incident, told Today's Zamman: "Police were shouting 'Drop your bag, drop your bag.' And the woman was saying, 'I will not surrender.'"
"The police warned her again, 'Drop your bag or we will have to shoot you,' and the woman said, 'Shoot'."
Another female assailant who was involved in the attack is believed to be at large.
"We are working with Turkish authorities to investigate the incident. The Consulate General remains closed to the public until further notice," a US consular official said.
The latest attack took place days after Turkey offered its bases to the US-led coalition for operations against Islamic State (Isis).
The incident also coincides with a string of similar violent attacks in many parts of Turkey. The Kurdistan Workers' Party (PKK) is believed to be behind some of these attacks.