London (AFP) - London's leading index ended lower on Thursday as investors worried over reports of increased Russian interference in war-torn Ukraine.
The benchmark FTSE 100 lost 0.36 percent, ending on 6,805.80 points.
"The stand-off between Russia and Ukraine has flared up once again with reports coming out of Kiev suggesting fresh military incursions across the border," said analyst Tony Cross at trading firm Trustnet Direct.
The United States accused Russia of being "directly involved" in fighting in conflict-hit east Ukraine, after rebels appeared to seize swathes of territory from retreating government forces.
Ukraine has asked NATO for help.
"Keeping recent bullish sentiment in check is the blatant Russian-led offensive in Ukraine," added Capital Spreads analyst Jonathan Sudaria.
There has been increasing concern in Kiev and the West that Russia is sending troops into eastern Ukraine, although Moscow has repeatedly denied the allegations.
Back in London CRH led the risers, climbing 2 percent to 1,426 pence, followed by Tullow Oil, which added 1.39 percent to 731.
The day's worst performer was Hargreaves Lansdown, slipping 4.86 percent at 1,117, followed by Rio Tinto which dipped 3.79 percent to 3,209 pence.
Lloyds Banking Group (LBG) was the most traded stock, with 72.03 million units changing hands, followed by Vodafone with 32.09 million.
On the currency markets, the pound was trading at 1.6577 at around 5.07pm, up from $1.6567 around the same time Wednesday. It also rose to 1.2581 euros, from 1.2552 euros over the same period.