Every sector on the UK stock market was either flat or registering losses on Monday as investors scaled back risk appetite amid escalating tensions between Ukraine and Russia.The crisis in Ukraine stepped up a gear over the weekend as Moscow increased its military presence in the Crimea region of the Black Sea. The move has been condemned by the G7 who labelled it as a "violation of Ukraine's sovereignty", prompting calls for potential trade sanctions and visa restrictions against Russia in retaliation.Industrial metals and mining stocks were by far the worst performers in London with sector heavyweights EVRAZ and Ferrexpo suffering heavy losses of 12% and 10%, respectively. EVRAZ is a steel, iron ore and coal producer with a large number of operations in Russia and Ukraine, while Ferrexpo's primary iron ore projects are located in Ukraine.Others in the sector, including International Ferro Metals, Talvivaara Mining and London Mining, were also trading in the red in afternoon trade.Disappointing data from China also weighed on market sentiment today after figures showed that manufacturing activity contracted for the second straight month. The HSBC/Markit manufacturing purchasing managers' index fell from 49.5 to 48.5 in February, though this was in line with expectations."Mining companies have been hit hard by the report that manufacturing in China did in fact drop to a seven-month low. A cooling off in home building will make matters worse for the mineral extractors," said David Madden, Market Analyst at IG.Top performing sectors so far todayBottom performing sectors so far todayIndustrial Metals & Mining 861.51 -10.48%Financial Services 7,888.93 -3.02%Construction & Materials 4,769.84 -2.60%Technology Hardware & Equipment 1,188.82 -2.45%Media 6,076.13 -2.42%BC