Turkish police arrested 11 people over the murder of an American woman who disappeared while visiting Istanbul last month, police and the local media reported Sunday.

The body of 33-year-old Sarai Sierra, a mother of two, was found on Saturday near Istanbul with fatal head wounds, the Radikal daily reported.

“We have confirmed that she was murdered by way of impacts on her head. But we need to conclude the investigation before details emerge,” Istanbul police chief Huseyin Capkin told reporters on Sunday, according to AFP.

She was also stabbed several times in her abdomen, but there was no sign of rape or theft and she was still wearing jewelry when police found her, the Milliyet newspaper reported.

Turkish police had been searching for Sierra after her family reported her missing on January 21, the day she was due to return home to New York.

The Hurriyet daily newspaper, along with other media outlets, reported that Istanbul police have arrested 11 suspects but gave no further details.

There have been speculations that the woman’s body might have been dumped in a blanket Tuesday night on the main road near the ancient walls of Istanbul, Hurriyet reported, citing a possible eyewitness.

“I saw a man removing something from the back seat of a car,” the eyewitness was quoted as telling police. “Then I saw a hand there.”

Police had initially detained a Turkish man named Taylan K., who is believed to be the last person to see Sierra before she went missing, but released him after questioning, according to local reports.

The two had reportedly met online four months ago.

Hurriyet speculated that Sierra might have been tricked into trying to smuggle drugs into the United States, citing an anonymous retired agent from the U.S. Drug Enforcement Administration.

Capkin said, however, that there was no indication that she was involved in such a scheme. “She was a lonely wanderer,” he said.

While Turkey has not been considered a safe destination for Jews or Israelis since the 2010 Mavi Marmara flotilla incident, until recently the country was considered a relatively safe travel destination for other nationalities, visited by millions of tourists every year.

On Friday, however, there was an attack on the U.S. embassy in Ankara, resulting in the death of two security guards.

The Revolutionary People’s Liberation Party/Front (DHKP/C), a group that is outlawed in Turkey, claimed responsibility for the attack, justifying it as retaliation for American policy in Iraq, Syria, Egypt and Libya.