GWEN IFILL: Next, the violence in Syria, where the government of Bashar al-Assad has stepped up its deadly crackdown, one week after agreeing to negotiate with the dissidents. More than 3,500 people have been killed over the last eight months, 60 of them in the last few days in the city of Homs.
Margaret Warner has more.
MARGARET WARNER: Only rarely have foreign journalists been able to report from Syria since the uprising began. But independent British-Iranian journalist Ramita Navai entered the country in September with freelance producer Wael Dabbous.
In this excerpt, Navai is holed up in an activist safe house in the town of Madaya.
RAMITA NAVAI, "Frontline": On the third morning, Abu Jafar tried to find out the latest news on the militia and army.
It's the first Internet log-in of the day, and he's just checking in with all the other coordinators and activists around Syria to find out what the news is.
Activists from outside town had posted footage of the armed forces entering Madaya.
MAN (through translator): These are the militia vehicles.
RAMITA NAVAI: So now you can see some white pickup trucks filled with, it looks like, armed men. And he says that that's Syria's militia.
These militia gangs, locally called shabiha, are Assad loyalists. The opposition accuses them of terrorizing their neighborhoods. Three hours later, Abu Jafar received a call from a lookout.
MAN (through translator): Where were they raiding?
RAMITA NAVAI: They confirmed the shabiha were conducting violent house-to-house searches. The lookout warned they were kicking down doors on our street.
Sounded like they were being knocked down right outside the flat.
MAN: Get the door.
RAMITA NAVAI: OK. Right. They're just telling us to lock the door.
MAN: Keep it.
RAMITA NAVAI: Yes. Keep it in there.
Malik, Mohammad and Abu Jafar all hid in the attic. They told me not to hide, but to have my passport ready to show that I wasn't Syrian.
We now hear from right outside the door, so I'm putting the camera away.
We hid our camera, but used a cell phone to film. I could hear the screams from next door as the militia raided the house. A mother was pleading with them not to take her son.
WOMAN (through translator): My son!
MARGARET WARNER: And Ramita Navai joins us now.
And, Ramita, welcome.
RAMITA NAVAI: Thank you.
MARGARET WARNER: This is quite a powerful piece.
Tell me, now, how did you manage to get into Syria and move around the way you did?
RAMITA NAVAI: We were really lucky in that we got tourist visas, so we flew into Damascus posing as a couple on holiday. We were very careful not to take in lots of camera equipment. We had one camera. It was about that big. So it looked like a home video camera, the kind that tourists have.
MARGARET WARNER: And then it appears that you plugged right into some sort of an activist network that helped you move around. Explain all that.
RAMITA NAVAI: Exactly. We were effectively embedded with the activists.
It's a big network. It spreads right across the whole country. And we really couldn't have made this film without their help. So, everywhere we went, they -- we took our lead from them. They would help us get to places. And they kept us safe.
MARGARET WARNER: And they had quite a lookout system. You refer to it in that little clip.
RAMITA NAVAI: Yes. So, if we were traveling into town, for example, we'd travel in a convoy. There would be lookouts out ahead. They would be communicating with each other via walkie-talkies, two-way radios, just in case we came to an army checkpoint, so the cars at the back could all turn around. It's really quite a sophisticated operation.
MARGARET WARNER: Now, I was reminded again just re-watching that clip that they really took a risk doing this with you.
For instance, when you film people talking, you're filming them here below, but, you know, the secret police could figure out who those people are. Why do you -- did they tell you why they did this, why they gave you this access, why they really facilitated this?
RAMITA NAVAI: Well, we took their safety really seriously. And this is something that we discussed with them for a long time before we actually flew into Syria.
It's a huge responsibility. We really needed to keep these people safe. We changed a lot of voices in the film, altered voices. But they are desperate to get this story out. And they are willing to risk their lives. And they do that every time they go out to the streets and protest.
As you know, the security forces fire indiscriminately at these protests. So, they said to us, you know, if we don't get this story out, the whole world will forget it us. We will be forgotten.
MARGARET WARNER: Now, one of the most vivid or sets of sequences in your film has to do with the secret hospitals. Tell us about that.
RAMITA NAVAI: This was one of the most upsetting and depressing parts of the story that we covered actually, because we really realized that you're not safe anywhere if you're a protester, not even in hospital.
So, a doctor told us he had seen with his own eyes dozens of injured protesters dragged out of their hospital beds by the security forces who raid hospitals looking for anyone who has been at a protest. And this doctor said it was a really familiar pattern that he saw.
A protester would be dragged out of his bed even if they had superficial injuries. A few weeks later, their dead body would be delivered to their families.
MARGARET WARNER: And so you went to, they looked like makeshift clinics that they -- in other words, people just don't go to hospitals anymore, the real hospitals.
RAMITA NAVAI: Exactly. People are too scared. So they go to -- they call them secret hospitals.
They're usually in people's backrooms, in safe houses. And they're kept hidden there, for fear of raids, of being caught. And the doctor that we spoke to was terrified treating these patients. He said over 10 of his colleagues were in prison simply because they treated injured protesters.
MARGARET WARNER: Now, since you left, the military has begun this -- and the security forces -- assault on Homs. And they're doing this kind of house to house, just as you see in your film.
What are you hearing from -- I know you still stay in touch with some of these activists.
RAMITA NAVAI: Yes.
MARGARET WARNER: Is this crackdown more intense than it was even a month or two ago?
RAMITA NAVAI: In Homs, it's extremely intense, because they're shelling the city. So it feels like a war zone. And parts of Syria felt like a war zone when we were there, and there was no shelling in Madaya.
So, at the moment, the situation is really bad. People are terrified. The economy in these towns have ground to a standstill. And people are just cowering in their homes.
MARGARET WARNER: Now, you got to know some of these activists well. Do you sense -- and I know I'm asking for a judgment here, but that they have the will, but also the means to withstand this kind of crackdown, this kind of assault?
RAMITA NAVAI: They didn't have the means. They still don't have the means.
And that's why I think that this uprising is going to take a bloody turn, because the activists I have been speaking to have said that they want to arm themselves. They say they think that's the only way that they can survive and that's the only way they can protect themselves. So I think we're going to see a real shift in what's happening.
MARGARET WARNER: Ramita Navai, a really fine piece of work. Thank you.
RAMITA NAVAI: Thank you so much.