London, England (CNN) -- Bomb attacks by dissidents in Northern Ireland nearly quadrupled over the past six months from the period before, a report from the Independent Monitoring Commission said Thursday.
Dissident republicans have steadily increased the number of improvised explosive devices they have deployed and detonated over the past two and a half years, the commission said. Since May, the number of devices deployed was roughly double that of the previous six months -- and the number detonated went up nearly fourfold, it said.
The findings by the commission, set up nearly seven years ago by the British and Irish governments, are in the latest and last of its biannual reports on the paramilitary and security situation in Northern Ireland.
While the number of bombings has gone up, there have been no deaths from bomb attacks and no one has suffered life-threatening injuries.
Still, the commission said, "the high level of dissident activity would undoubtedly have led to many more deaths, injuries, and destruction had it not been for the operations of the law enforcement and security agencies north and south (in Northern Ireland and the Republic of Ireland) and their ever closer cross-border co-operation".
It said that in both Northern Ireland and the Republic, about three times the number of dissidents have been charged with terrorist offenses in all of 2010 than in 2009, and the number of arrests has nearly doubled.
Dissident republicans are those who refused to accept the 1998 Good Friday peace settlement and power-sharing deal negotiated and signed by mainstream republican leaders such as Sinn Fein's Gerry Adams and Martin McGuinness.
Groups like the Real IRA and Continuity IRA broke away from the Irish Republican Army, also called the IRA, which fought for decades against British rule in Northern Ireland. The IRA agreed to a process of decommissioning under the Good Friday deal, something the dissident republicans do not accept.
The report also said the two factions of the Real IRA have been the the most active and dangerous of all such groups, conducting 18 attacks on members of the security forces and those associated with them. Each faction has its own structure and "army council," the report said.
CNN