Timeline - Increased dissident attacks in Northern Ireland

(Reuters) - Police say the risk of violence in Northern Ireland is severe, meaning they regard attacks as likely, while Ireland's justice minister has said the threat is as high as at the height of the province's "Troubles."

The Independent Monitoring Commission for Northern Ireland and the UK parliamentary Intelligence and Security Committee have also noted a marked increase in dissident republican activity, adding the threat remained very real.

Although extremely serious, analysts have said recent attacks did not compare with the three decades of fighting that killed 3,600 people and they doubt they could cause the peace process begun by the 1998 Good Friday Agreement to unravel.

They estimated some 300 dissidents actively opposed the peace process and that youths have been recruited to their cause in hardline republican areas.

Today's numbers compare with the estimated 10,000 who passed through the ranks of the Provisional Irish Republican Army during its campaign of violence.

Here is a list of the biggest attacks carried out by dissidents since their campaign hit the headlines in March 2009 with the killing of two British soldiers who had been about to leave for a tour of duty if Afghanistan:

- March 2009 - The Real IRA, claimed responsibility for killing two British soldiers at the Massereene Barracks in Antrim, the deadliest act of violence in Northern Ireland in over a decade.

- Two days later the Continuity IRA, another splinter group formed out of the Provisional IRA and that also seeks the removal of British influence from the province, said it shot dead a police officer in Craigavon, 25 miles (40 km) southwest of the Northern Ireland capital Belfast.

- September 2009 - Army experts in Armagh made safe a device with about 600 lbs (272 kg) of homemade explosives which police said targeted its officers and could also have hit nearby homes. The bomb was bigger than the one used in the Omagh bombing.

- October 2009 - A car bomb injured a policeman's girlfriend as she drove away from his home less than half a mile from police headquarters in Belfast.

- November 2009 - Gunmen ambushed and shot at police in the village of Garrison, 25 miles (40km) from Enniskillen where a 1987 bomb killed 11 people, one of the deadliest attacks during Northern Ireland's 30 years of sectarian strife.

- A car laden with a 400 lb (180 kg) bomb partially exploded at the Belfast headquarters of the police watchdog a day later.

- January 2010 - A policeman had to have his right leg amputated after a booby trap bomb exploded under his car in County Antrim. Police said dissident republicans were clearly behind the attack.

- February 2010 - The Real IRA was also blamed for a car bomb attack outside a courthouse in Newry, as well as gun and pipe bomb attacks on police stations in Belfast and on towns near the border with the Republic of Ireland. The Newry bomb contained what police estimated to be 250 pounds (115 kg) of explosives and caused extensive damage, although no-one was hurt after police evacuated the area following a tip off.

- February 2010 - The Real IRA, the dissident republican group behind Northern Ireland's single worst atrocity, the August 1998 Omagh bombing which killed 29 people, claimed responsibility for shooting dead a man in Derry in February.

- March 2010 - Police came under gun attack south of the town of Newry, while investigating a security alert that led to the closure of the Belfast-to-Dublin railway line.

The alert on the railway line began the day before, the same day as a series of coordinated bomb alerts caused major disruption in Belfast. They were all eventually declared hoaxes.

(Reporting by Barbara Lewis and Ian Graham; editing by Padraic Halpin)