Nairobi, Kenya (CNN) After a bloody terror attack nearly two years ago, Kenya's Westgate shopping mall reopened its doors to shoppers Saturday.

While many of the same stores have moved back in, the mall's reopening has met with a mixed reaction from survivors of the assault that left 67 people dead, Kenyans and foreigners among them.

The Somali terror group Al-Shabaab, an affiliate of al Qaeda, claimed responsibility for the bloody four-day siege at the upscale mall in Nairobi, which began on September 21, 2013.

Many of those who survived, like Shamim Allu, still bear the scars. She was shot five times, and continues to suffer from grenade shrapnel in her body.

"They still twinge up, because they are quite prominent, these are really tiny ones, if you feel them they are little balls of metal," she said.

Allu was taking part in a children's cooking competition when the assault began. She cradled a small boy she didn't know as he died in her arms.

"As a mark of respect for the ones who died there, I would not be able to walk in there," she said. "I think it's really sad that it's opening up as a shopping mall. I would have been happy if it had opened up as a memorial site, or a religious place, where everyone who was injured can go."

Unanswered questions

There is no visible evidence of the horrors that unfolded over the course of the brutal 80-hour siege. Walls have been plastered and repainted, shattered glass replaced.

JUST WATCHED CNN goes inside Nairobi's Westgate mall Replay More Videos ... MUST WATCH CNN goes inside Nairobi's Westgate mall 02:20

But it will take longer to overlay people's memories of what they saw.

Surveillance video from the mall showed gunmen casually shooting some civilians. They reportedly also tortured some hostages, according to military doctors who saw evidence of severed hands and noses. They hanged others.

Kenyans are still asking, how could this attack have happened, who carried it out, and what happened to the killers?

"It bothers me for the families, the people who were lost there, that our questions are not answered and nothing has been brought to surface," another attack survivor told CNN.

She asked to remain anonymous because she is afraid of speaking out.

She worked at a jewelry store that is reopening in Westgate. She recalled how she was having lunch when a hand grenade rolled towards her table, killing her waitress.

"She died right in front of me, she took her last breath and I experienced it," she said.

'Life has to go on'

But Elijah Musyoka, who works at the same jewelry store, is determined to return to work at Westgate.

"You know, life has to go on. If we don't go back or we give up, then these people they will think we are weak or cowards, we have to show them we have courage," he said.

Musyoka and others hid on the rooftop of the mall for three hours, watching gunmen pump bullets mostly into women and children.

Although they differ on whether Westgate should open up or not, all three agree they're survivors, not victims.

Civilian responder: We need to show resilience

For Abdul Haji, a civilian who entered the mall after the attack started -- trying to rescue his brother and others who were stuck inside -- it's also a mixed picture.

Haji, a licensed firearms carrier, and a group of other men who went in with him are credited with helping perhaps as many as 1,000 people escape the mall.

Photographs captured some of their heroic efforts, including Haji persuading a 4-year-old girl, Portia Walton, who was trapped under a table with her mother and siblings to run to them, moments after the civilian responders exchanged fire with the terrorists.

"Amidst all the noise and the tear gas, we asked Portia to run towards us to safety and she did," said Haji. "She was very brave and I still keep telling everybody that Portia is my hero."

With memories of what he witnessed still fresh in his mind, Haji is not sure if he'll ever re-enter Westgate.

For him, going to the mall with friends should be about having fun, he said. "I would expect to be laughing and joking around and I don't see myself doing that at the Westgate because of what happened. I don't know if that's going to be respectful to the victims."

But at the same time, he said, "We need to show the world that as a country and as the city of Nairobi, that we are resilient and we need to move on with our life. I am just hoping that the Westgate probably will have a small memorial corner for the people, because we need to remember the victims every year at least."