The clashes came as Yugoslav leaders vowed to take action against ethnic Albanians who they blame for attacks on Serbs in the buffer zone separating Kosovo from the rest of Serbia.

CNN: Fighting on Macedonia-Kosovo border

The suspicion must be that what we are seeing is a co-ordinated movement by two of the countries that have most vehemently opposed tough international action to restrict emissions over the last few years - perhaps as a buffer in case the EU starts looking at other trade-related climate measures, such as border adjustments, more seriously.

BBC: EU's aviation charge is a drop for China's airlines

Today it has about four times greater resources than what was available to it when that action was taken in 2009, so we think that is a very important buffer for the international community.

WHITEHOUSE: Press Briefing