Two elderly men living alone in Galway and Kerry were found murdered last week.
Earlier this month gardai detained several people at Dublin preparing to board a ferry with a vehicle believed to have been stolen from the home of an elderly woman in Co Tipperary. The line of inquiry involves suspects in the Irish gypsy community.
The attacks on farmers came in areas where emigration and cutbacks in the garda have left elderly people vulnerable to robbery. The murder of a 44-year-old woman last week in Milltown, Co Kildare, sparked a national outcry and put presure on the justice minister Nora Owen to improve policing.
Last week's murders began with the separate killings of two farmers. The battered body of Patrick Daly, 69, was found dumped in a well near his 120-acre dairy farm near Killarney.
A post-mortem examination showed the bachelor died from massive head injuries. He may have been kicked and attacked with two blunt weapons.
Though there were no obvious signs of a break-in, it is known he withdrew a large sum of money from a building society six days before his body was discovered. He had been dead since Saturday.
The body of Tommy Casey, 68, was found with his hands and feet tied, lying in a pool of blood on the kitchen floor of his ransacked farmhouse at Oranmore, near Galway.
The killings follow a series of robberies in country areas. On 17 January an elderly Cork woman was attacked by two men in her home. In Co Clare an 87-year-old man was tied up and robbed. The next day a woman of 81 was beaten by two men who ransacked her home. On 3 January there were seven robberies of elderly people in the rural Midlands and West.
Chief Superintendent Tom Monaghan said suspects included a number of members of the travellers' community. He said: "I know that the vast majority of the travelling community are law-abiding and will condemn unreservedly those crimes. I am appealing to them if they have any suspicions about who may be responsible to get in touch with us."
Detectives believe as many as 90 per cent of the robberies may all be the work of perhaps four groups of related travellers.
Adding to the widespread concern over violent crime in the republic was the discovery on Wednesday of the semi-naked body of Joyce Quinn, 44, who owned a grocer's shop at Milltown, Co Kildare.
Mrs Owen will present a package of measures to cabinet to strengthen garda effectiveness and ease the shortage of prison space. If approved this will allow construction of a new prison in Co Roscommon, deferred last year because of budget pressures.
Moving segregated republican prisoners from Portloise jail, where around 60 cells are vacant, will also create more space.
Mrs Owen intends decentralising garda command by creating four autonomous regional divisions. The Taoiseach, John Bruton, last week complained of "an endless paper chase" of centralised bureaucracy in the force.
With space for just 2,200 inmates, Ireland has a chronic shortage of prison spaces, leading to widespread and controversial early releases. A liberal bail regime has also sparked anger over offences often committed by heroin addicts awaiting trial or sentence.Reuse content