Forensic teams are carrying out a detailed search of the area
There's growing concern for the peace process after another shooting in Northern Ireland.
For the first time in more than 10 years, a police officer has been killed.
Constable Stephen Carroll, 48, became the first member of the new Police Service of Northern Ireland (PSNI) to be shot dead on duty.
He was attacked on Monday night in Craigavon, about 30 miles south-west of Belfast, 48 hours after two soldiers were shot dead outside their barracks in Antrim.
A dissident republican group, the Continuity IRA, claims to have carried out the murder.
Newsbeat listeners have been texting in their response to the killings all day.
Natasha was heading to university in Magee, Derry, when she heard about the latest shooting. She says they are extremely frightening.
She said: "It feels like a rug being pulled out from under you.
"I know it's the work of a very small minority but there's always a fear that the troubles could start up again."
One person didn't include their name but said: "I'm 23 and I've grown up with family who were in the army and the police during the troubles.
"Personally I think the the army should never have left and they should never have got rid of the RUC. Nobody feels safe any more."
The Royal Ulster Constabulary (RUC) became the new PSNI in 2001.
Kieran from Lisburn said he was asked by his young cousin two weeks ago what the troubles were.
He said: "As a 26-year-old I was so happy that the country has progressed so much that this 13-year-old is oblivious to the bitterness and hatred which plagued Northern Ireland for so long.
"There is no way we should sit back and allow a few mindless animals to destabilise the decent work done to get us this far."
Ryan in Newtownabbey said simply: "The Real IRA shall never change the will of the good people of Northern Ireland."
Many Newsbeat listeners have texted in to say they're scared that the recent killings may lead to more violence.
Melanie in Ballymoney said: "The recent events here in Northern Ireland are disgusting and really scary.
"We thought all this was behind us. My daughter is six months old and it's awful to think she might grow up with the conflict raging again.
Gordon Brown said there would be 'no return to the old days'
"No-one supports these dissidents. What or whose cause do they think they are fighting for?"
Alison is 20 and from Northern Ireland. She said: "It's just unbelievable. No-one wants to go back to the times of the troubles.
"These dissident groups are stuck in time, they can't accept that the people of Northern Ireland have moved on.
"Their actions will not break the peace but I think will unite people against the dissident groups."
Emma, 20, is frightened. She said: "I live in County Armagh where the latest shooting is and I find it frightening that the troubles will happen again.
"It really makes you think twice about living here."