BELFAST, Northern Ireland (CNN) -- Government ministers from Britain and Ireland on Monday said they would implement new security measures aimed at taking "off the streets" the kind of terrorists that carried out Saturday's deadly bombing in Omagh.

Britain's Northern Ireland Secretary Mo Mowlam said security would be stepped up along the border between Northern Ireland and the Irish Republic.

She said she wouldn't reveal other details, "because it would be stupid" to do so.

Police suspect that a dissident faction of the Irish Republican Army known as the Real IRA carried out the Omagh bombing.

Anti-British republican guerrillas have often used the Irish Republic as a staging ground for their attacks in the British province.

Mowlam, standing beside Irish Justice Minister John O'Donoghue, described those responsible for the car bomb as "animals."

She told reporters that internment without trial of members of guerrilla groups was neither ruled out nor ruled in, although she did not think it was a good idea.

Rather than "taking a sledgehammer to crack a nut," as internment had been when it was used against the IRA in the 1970s, she wanted to make it easier to prove that suspects belonged to proscribed guerrilla groups.

O'Donoghue, who had held lengthy talks with Mowlam and police chiefs from both sides of the border, said cooperation between the Irish police and their colleagues in Northern Ireland had never been better. "Together we are going to fight this," he said.

Reuters contributed to this report.