Mr Clinton's spokesman, George Stephanopoulos, said the Maria was stopped off the Seychelles, south-west of Somalia. He said it was carrying arms believed to be headed for Somalia.
He did not say which US or allied forces were involved or whether the ship was still being detained, but added it was one of five Serbian ships blocked over the last month. He also cited success along the Danube in preventing shipments by Serbia.
Mr Clinton, during a morning appearance with a group of mayors, said he wanted to tighten sanctions against the aggressors without endangering allied troops on the ground in the former Yugoslavia. 'I don't think there's any question that when the Serbs take an area and then run all the Bosnian Muslims out, then that means that they are succeeding,' he said. 'And they have succeeded in running some people out of communities.'
Mr Stephanopoulos said the US had two teams in Europe discussing ways to stop the transfer of goods and money to the Serbs. 'The entire effort is designed to crack down on the Serbians, to inflict real pain and real price for the actions they're taking,' Mr Stephanopoulos said.
He said that Mr Clinton was looking at 'further actions that would help stop' Serbian aggression.
The White House discussed the actions involving Serbia as the commander of the UN peacekeepers in Bosnia tried to negotiate safe passage out of besieged areas for thousands of desperate Muslims. Mr Clinton said UN relief workers 'have to be defended for trying to facilitate their escape, not for supporting ethnic cleansing. . . . The United Nations' operation there is now simply trying to save their lives.'
He said the US was looking for ways to tighten sanctions without endangering allied troops or alienating Russia, which has historic ties to Serbia. Russia has pledged to aid in a US effort to air-drop supplies to the region.
The President disputed criticism that the air-drops had exposed Bosnian Muslims 'to any more danger than they otherwise would have been exposed to'.Reuse content