HONG KONG (AFP) - Fears that the eurozone debt crisis will spread continued to take their toll on Asian markets Thursday, as stocks fell and the euro hovered near one-year lows following deadly riots in Greece. Violent demonstrations in Athens, where three people were killed in a bank firebombing, rattled investors who fear a 110-billion-euro ($145b) EU-IMF bailout for Greece could prove insufficient Concerns are also mounting that the deal will fail to shield Spain and Portugal from crippling market pressures. Investors in Tokyo had their first chance to react to a recent global sell-off after a three-day national holiday, with the headline Nikkei index tumbling 3.27 percent, or 361.71 points, to close at 10,695.69. Hong Kong fell 0.96pc, or 194.13 points, to close at 20,133.41. The index has fallen more than 4.5 percent this week. Investors were also spooked by a warning from Moodys Investors Service on Wednesday that it could cut Portugals Aa2 sovereign rating by up to two notches. Greek neighbours are unlikely to let Greece default. But investors will likely remain wary as long as there are uncertainties over the countrys fate and fiscal problems in other euro-zone economies, Kwak Joong-bo at Hana Daetoo Securities in South Korea told Dow Jones Newswires. Markets have increasingly lost confidence in the eurozone, with the outlook worsening after deadly riots in Athens and fears that other European nations could face similar financial risks. Greek President Carolos Papoulias called on the country to step back from the abyss after a day of often violent protests against the latest budget cuts and tax hikes. The ailing euro hovered near 14-month lows in Asian trade as bargain buying halted its recent slide, but mounting eurozone debt worries continued to pressure the currency, dealers said. The euro bought 1.2814 dollars in Tokyo morning trade, up from a 14-month low of around $1.2800 in New York late Wednesday. The single European unit also edged up to 120.33 yen from 120.23 yen. Meanwhile Sydney gave up 2.16 percent, or 100.8 points, to close at 4,573.2, with investors continuing to sell off resources stocks following Prime Minister Kevin Rudds announcement of a 40 percent tax on mining profits. Miner BHP Billiton ended 2.94pc off while rival Rio Tinto fell 3.79pc. Shanghais composite index dived 4.11 percent, or 117.45 points, to an eight-month low of 2,739.70 on fears of contagion from the Greek crisis as well as Chinas moves to cap lending on the mainland. Coal firms were also sold on concerns over the Australian tax plan. Chinas central bank announced at the weekend it would raise banks reserve requirement ratio by 50 basis-points, the third increase this year, as it tries to rein in lending amid fears of a property bubble and economic overheating. Asian markets took a weak cue from Wall Street where shares fell 0.55 percent Wednesday.