Prosecutors in Istanbul got a court order Monday for authorities to take blood and DNA samples from 21 people already questioned in the death of a New York city woman, state media reported.

Sarai Sierra, a 33-year-old mother of two, went missing Jan. 21 while on a solo vacation in Istanbul. Her body was found 12 days later, near the remnants of the city's ancient walls. Police said she had suffered a fatal blow to the head.

Turkish authorities finished an autopsy Monday on Sierra and gave DNA samples from it to a crime lab for testing, the state-run Anadolu Agency reported.

After that, Istanbul prosecutors got the court order but did not identify the possible suspects, the agency reported.

Police on Monday were still scouring the area where the body was found for clues with the help of sniffer dogs, it said.

Turkish police had set up a special unit to find Sierra and her husband, Steven, traveled to Istanbul last week to help in the search. Steven Sierra talked to police again on Monday, this time as a plaintiff in the case, Anadolu said.

The Milliyet newspaper said the forensic lab will examine samples from Sierra's fingernails as well as hair and other samples from a blanket found near her body. It said some nail scrapings suggest she may have tried to fight off her attacker or attackers.

Sierra, whose children are 9 and 11, had left for Istanbul on Jan. 7 to explore her photography hobby and made side trips to Amsterdam, Netherlands and Munich, Germany. She was to have traveled with a friend, but the friend cancelled.

Sierra was in regular contact with friends and relatives during her vacation and had told them on Jan. 21 _ the day she was due to board her plane back home _ that she was going to visit Galata Bridge, which spans Istanbul's Golden Horn waterway, to take photos. She never checked into her flight.

In New York, Sierra's mother, Betsy Jimenez, said her two grandsons did not know what had happened to their mother.

"Their father is going to talk to them when he comes back and we'll all be there to support him," she told NBC's Today show on Monday

Jimenez said it was Sierra's first overseas visit.

"She wanted to go take pictures of the history of the place ... and she was interested in taking pictures of the bridges. She was fascinated with the bridges," Jimenez said.

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