Nairobi mall survivor describes hiding among the dead and dying

(CBS NEWS) NAIROBI, Kenya -- An army of forensic experts that includes FBI agents spent today scouring the shopping mall in Nairobi, Kenya, that was attacked over the weekend. A terrorist group from Somalia called al-Shabab laid siege -- killing at least 72 people. Dozens more are still missing.

Sneha Kathari-Mashru is one of the survivors. She is thankful she left her two-year-old son, Shane, at home last Saturday when she met her friends for coffee at the mall -- the day a gunman burst in and opened fire.

Sneha Kathari-Mashru
CBSNews

" He was so heartless and inhuman because he was just shooting randomly," she said. "He did not have the sense that he was shooting a small innocent child or a lady or a man. He just kept spraying his gun at whoever he felt like. "

She said he only stopped when a man stood up and identified himself as a Muslim.

"He had his hands in the air," she said. "And they had some small conversation, and I just saw him reciting Allah, Allah."

The man and his young family were shown to safety.

Her friends, like so many victims, had been shot. She tried to hide among the bodies of the dead and wounded, near a teenage boy who was bleeding to death.

Sneha Kathari-Mashru with her son Shane
CBSNews

"I drew a lot of blood with my hand and I tried to spread it on myself, on my arm, so just in case the terrorist comes he would think I was dead or probably injured and not attack me," she said.

Her plan paid off. She played dead for more than an hour before she was rescued.

But she had to leave a friend behind.

New video released by the Kenyan government shows the full extent of the siege's destruction.
New video released by the Kenyan government shows the full extent of the siege's destruction.
CBS News

"I just asked her if she could get up because there's someone who had come to rescue her," she said. "And she goes like, she bravely gave me a smile and she goes like, 'Sneha, just go. I cannot get up. I've been shot at the back.'"

Investigators, meanwhile, are trying to figure out whether a British woman was involved with the terrorists, and Interpol put out an arrest warrant for her today.

Her name is Samantha Lewthwaite. She's a 29-year-old Muslim convert, the daughter of a British soldier. She's known to have links with al-Shabab. In Briton, she's known as the "white widow." She's the widow of one of the suicide bombers in the 2005 London transit bombings.

Now she's thought to have resurfaced here after disappearing from Briton, somewhere in this region between Somalia and Kenya. It's clear the Kenyan authorities want to speak to her now but it's worth noting there was no mention of the attack at the Westgate Mall in the request to Interpol.