The Nato operation to arrest two Bosnian Croats charged with war crimes was carefully planned: the Dutch troops who played a key role are reported to have been specially flown into Bosnia. The operation took place in the zone patrolled by British troops, like a similar one against Bosnian Serb suspects last July. And it came as President Clinton was expected to announce that American troops would stay in Bosnia beyond next June's deadline. Our diplomatic correspondent, Barnaby Mason, looks at the possible connections:

The mandate of the Nato-led force in Bosnia, S-for, gives it the authority to arrest those charged with war crimes when it comes across them in the course of its normal duties. But that's now being interpreted more toughly, so that when suspects are identified and located, a carefully planned and co-ordinated operation can be mounted - a description officially given to the arrest of the two Bosnian Croats.

Reports say Dutch troops were specially flown into Bosnia for the operation. The Nato spokesman in Brussels, Jamie Shea, put it this way:

"Obviously, we continue to watch very closely the movements of all indicted war criminals. It's not so much that we plan these things in advance - that's sometimes very difficult to do; it's more a question of NATO commanders being on the look-out for suitable opportunities to be able to detain these individuals."

Dr Shea said there was no direct link between the arrests and any other event. But they are certainly very helpful to President Clinton, coming just a few hours before he was expected to announce a decision in principle to keep some American troops in Bosnia beyond the end of S-for's mandate next June. Demonstrating that results are being achieved in arresting suspected war criminals will help win the argument in Congress against those who want the troops brought home.

Mr Clinton is making a brief visit to Bosnia on Monday. It's reported that American troops provided back-up for the operation, which like last July's move against Bosnian Serb suspects took place in the area patrolled by British forces.