London (AFP) - Seven men appeared in court in Northern Ireland on Monday charged with "terrorist offences" including plans to target police officers and judges.

The seven were ordered to remain in detention following an investigation into republican militants opposed to the peace process in the province.

The court hearing revealed the allegations were based on 70 hours of secret recordings by the MI5 secret service in a house in Northern Ireland.

"The arrest and charging of these individuals with what are very serious terrorist offences clearly demonstrates our commitment to investigate all those involved in terrorism," said Kevin Geddes, a senior officer from Northern Ireland's Serious Crime Branch.

All seven were charged on Sunday with membership of a banned organisation, while six of them also face charges of conspiracy to possess explosives, firearms and ammunition and preparation for attacks.

The men are aged between 30 and 75, the police said.

In Monday's hearing in Newry a police officer answered only "correct" when asked by a prosecution lawyer if the bugged conversations showed that police officers and members of the judiciary "were discussed with a view to targeting them".

The hearing came after a rocket was fired late on Sunday at a police car in Belfast in what superintendent Muir Clarke branded "a completely reckless, callous attack".

More than 3,500 people were killed in the three decades of sectarian bombings and shootings in Northern Ireland known as "The Troubles" before an historic peace agreement in 1998.

The Good Friday peace accords largely ended the violence and paved the way for a devolved power-sharing government, although dissident republican groups opposed to peace are still active.