Traders adopted a cautious approach on Wednesday morning with UK stocks registering losses in morning trade ahead of a number of 'risk events' later in the week which have the potential to spark market volatility.Fears about impending US military action in Syria also hit investor sentiment today as support for a Western intervention continues to grow. Markets across Europe were trading in the red this morning, while stock futures in the US pointed to a weak start on Wall Street.The Senate Foreign Relations Committee last night gave the green light on a US attack on Syria, saying that the use of force "reflects the will and concerns of Democrats and Republicans alike". This comes ahead of the crucial vote in Congress next week on President Barack Obama's call for action against the Bashar al-Assad regime which he claims is responsible for the deadly chemical weapons attack against the Syrian people in August.It is set to be a busy end to the week with central-bank policy decisions expected on Thursday from the Bank of Japan, Bank of England and the European Central Bank. These will be followed by the all-important US jobs report on Friday which will be a large factor in the Federal Reserve's decision on whether or not to adjust current stimulus measures later this month.Services PMIs come in mixed"A combination of geopolitical concerns and hesitation before these big events forced us to look to economic data for fresh inspiration but readings from the Eurozone were less than impressive," said Market Strategist Ishaq Siddiqi from ETX Capital.After a series of better-than-expected manufacturing surveys from across the globe in recent days, data from the Eurozone services sector disappointed with activity growing by less than forecast in August. The Eurozone services purchasing managers' index (PMI) came in at 50.7, worse than the 51 estimate. Eurozone retail sales meanwhile increased by just 0.1% in July (forecast: +0.2%).In contrast, there was no letting up in the recent string of strong UK data this morning with the outlook for British economy continuing to brighten. The UK services PMI rose from 60.2 to 60.5 (forecast: 59.7), the highest level since December 2006."Following surprisingly strong gains in August's manufacturing and construction surveys, today's services result at face value points to quarterly [economic] growth in Q3 not far off a rip-roaring 2%," said Martin Beck, UK Economist from Capital Economics.FTSE 100: Airline stocks sink after Ryanair profit warningAirline peers easyJet and IAG were flying lower this morning after a gloomy outlook by Ryanair on the back of the hot weather in Northern Europe over the summer. The company scaled back its full-year profit guidance after worse-than-expected bookings but said that it could even fail to meet these forecasts if fares and yields continue to weaken over the coming winter.Hargreaves Lansdown fell despite reporting record annual figures this morning. Full-year pre-tax profit rose 28% to £195.2m as the financial services company took on more clients and increased assets under administration by 38% rise in AuA to £36.4bn. Weighing on the price this morning could be Morgan Stanley's downgrade of the 'Diversified Financial' sector to 'neutral'.TUI Travel, Resolution and BHP Billiton were also heavy fallers after going ex-dividend, meaning that from today new investors won't be able to get their hands on their latest dividend payments. Others that went ex-dividend on the blue-chip index include Admiral, Aggreko, ARM Holdings, IMI, Land Securities, Serco Group and Shire.Even chemicals group Croda International was lower after going ex-div, shrugging off an upgrade by Exane BNP Paribas to 'outperform'. Sector peer Johnson Matthey however was a high riser after JPMorgan Cazenove raised its target price from 2,600p to 2,800p. FTSE 250: Phoenix lower after going ex-divMicro Focus and Phoenix were among the worst performersthis morning after going ex-dividend. A host of others were also trading without the rights to their latest payouts, including 888 Holdings, Betfair, Elementis, esure, Greggs, Hikma Pharmaceuticals, Jardine Lloyd Thompson, Michael Page International, National Express Group, Polymetal International, Regus, SEGRO and Xaar.Kenmare Resources was higher after Goldman raised its recommendation to 'conviction buy', while Salamander Energy was boosted by a Morgan Stanley upgrade to 'equalweight'.FTSE 100 - RisersVodafone Group (VOD) 206.30p +1.88%Johnson Matthey (JMAT) 2,960.00p +1.47%Whitbread (WTB) 3,151.00p +1.06%Petrofac Ltd. (PFC) 1,410.00p +1.00%BG Group (BG.) 1,259.00p +0.96%Fresnillo (FRES) 1,288.00p +0.78%Experian (EXPN) 1,140.00p +0.53%Shire Plc (SHP) 2,398.00p +0.46%Intertek Group (ITRK) 3,246.00p +0.19%Rio Tinto (RIO) 3,064.00p +0.18%FTSE 100 - FallerseasyJet (EZJ) 1,200.00p -6.25%TUI Travel (TT.) 331.90p -3.99%Resolution Ltd. (RSL) 312.60p -3.93%International Consolidated Airlines Group SA (CDI) (IAG) 284.00p -3.63%Persimmon (PSN) 1,102.00p -3.50%Associated British Foods (ABF) 1,845.00p -2.95%Hargreaves Lansdown (HL.) 1,001.00p -2.91%Carnival (CCL) 2,316.00p -2.89%BHP Billiton (BLT) 1,890.00p -2.38%Standard Life (SL.) 331.90p -2.32%FTSE 250 - RisersBumi (BUMI) 223.00p +6.85%Kenmare Resources (KMR) 28.51p +4.82%Fisher (James) & Sons (FSJ) 1,136.00p +3.93%Enterprise Inns (ETI) 150.10p +3.88%Dechra Pharmaceuticals (DPH) 708.50p +2.98%COLT Group SA (COLT) 112.50p +2.93%St. Modwen Properties (SMP) 295.80p +2.74%Balfour Beatty (BBY) 262.70p +1.74%Smith (DS) (SMDS) 271.90p +1.64%Daejan Holdings (DJAN) 3,830.00p +1.46%FTSE 250 - FallersThomas Cook Group (TCG) 134.90p -5.40%Micro Focus International (MCRO) 731.50p -5.06%Ashtead Group (AHT) 654.00p -4.87%Phoenix Group Holdings (DI) (PHNX) 722.50p -4.30%Berkeley Group Holdings (The) (BKG) 2,083.00p -3.52%Barratt Developments (BDEV) 303.90p -3.52%Amlin (AML) 377.10p -3.28%Taylor Wimpey (TW.) 100.00p -3.01%Mitchells & Butlers (MAB) 433.90p -2.97%Diploma (DPLM) 618.00p -2.68%BC