Northern Ireland First Minister Peter Robinson and deputy First Minister Martin McGuinness have spoken of their shock over the crash at Cork Airport today which claimed six lives.
Mr Robinson said: "This is a terrible tragedy and my thoughts are with the families of the bereaved.
"My thoughts are also with the injured and I hope that they will make a full and speedy recovery."
The deputy First Minister said: "I am shocked at this news and want to convey my condolences to the families, friends and loved ones of those who have lost their lives in the plane crash.
"My thoughts are also with those who have been injured."
"This is I think testimony to the unquestionable uncertainty of life.
"Families that start out either to do a day's business or to enjoy some pleasure have been thrust into circumstances that they could not have imagined."
The East Belfast Democratic Unionist Assembly member was briefed at Belfast City Airport and said he would be surprised if there were not people from Northern Ireland on the plane.
He added the Department for Regional Development would be making every support available to the grieving families and Health Minister Michael McGimpsey may also become involved.
Northern Ireland's Transport Minister Conor Murphy said he was in contact with his counterpart in the Republic in the aftermath of the tragedy.
Mr Murphy said: "My thoughts are with the families of those involved and I offer my sympathies to everyone affected.
"I have spoken to the Minister for Transport in the south, Pat Carey TD, and offered the support of my department to help in whatever way we can.
"I continue to be updated on the situation as more details emerge."
Lord Mayor of Belfast, Councillor Pat Convery, has said that his thoughts and prayers are with those who were on board the flight and their families.
"On behalf of the citizens of Belfast I extend my heartfelt sympathy to those families bereaved by this tragedy," he said.
"Our thoughts and prayers are with them as well as those who are being treated for their injuries in hospital".
The turbo prop aircraft travelling from George Best Belfast City Airport crash landed on a runway on the third attempt to land.
A Cork County council statement said six people had died and six were injured.
Unconfirmed reports on RTE had earlier claimed that eight people died in the accident.
The Manx2 commuter flight was en route from Belfast when it crashed in heavy fog just before 10am on runway 17.
The Irish Aviation Authority (IAA) said the aircraft made two attempts to land before crashing.
"It had been trying to land in foggy conditions. This was its third attempt to land," an IAA spokeswoman said.
An IAA statement said: "The aircraft made an approach to Runway 17 in low vis conditions and went around and did not land and attempted a second landing on Runway 35.
"The aircraft then went around a second time and came back for an approach to Runway 17.
"On the second approach to Runway 17 the aircraft crashed, Rescue and Fire crew are in attendance.
"There is a fire and debris has been scattered onto the runway and over a wide area."
Witnesses report hearing a loud bang. The aircraft, a 19-seat Fairchild Metroliner, is said to have burst into flames.
Debris has been scattered onto the runway and over a wide area.
Gardaí, fire crews and ambulances from across the city and county are responding.
Gardai are appealing to people to stay away from the airport and for motorists to avoid the area.
A Cork Airport spokesman said: "There has been a crash, a Manx 2 airline, commuter plane. The emergency services are on the scene."
The plane was operating a service from George Best Belfast City Airport to Cork.
A spokesman for George Best Belfast City Airport said: "We can confirm that the Manx 2 aircraft was scheduled to leave Belfast City Airport en route to Cork, flight number NM 7100.
"It left at 0812 this morning with 10 passengers and two crew on board. We understand there has been an incident at Cork airport involving this aircraft."
Manx2.com has set up a special helpline on 028 90427004.