Six people were arrested in Northern Ireland today on suspicion of attempting to import guns for use by republican paramilitaries.
Four men and two women were arrested by officers in the Belfast and north Antrim in an operation that involved the Garda, the FBI and Scotland Yard.
Police sources this evening were claiming to have smashed an international IRA arms smuggling plot.
A Police Service of Northern Ireland (PSNI) spokesman said the six were being questioned about the "illegal importation of guns into Northern Ireland by republican terrorists".
The PSNI said the operation that led to today's arrests dates back to 1999 when guns and component parts were discovered by postal staff in Coventry.
Police in Belfast said today those weapons had been posted from the United States, often in boxes containing toys, before being intercepted in England.
As part of the operation, four people were later convicted in Florida of firearms offences in September 2000. Later a number of the weapons turned up in the Republic where four men were jailed for guns offences last month.
Earlier this morning, police arrested eight people in Derry in a crackdown on loyalist paramilitaries.
A PSNI spokesman said seven men and one woman had been detained in the Waterside area of the city, where 12 searches were made. Searches were also taking place in Ballymoney, Co Antrim, he said.
The spokesman said the operation began early this morning. It is believed police were specifically targeting the activities of the Ulster Defence Association.