Mainland markets fall
China's Shanghai Composite index accelerated the pace of decline in the afternoon session, closing down 6.12 percent at its lowest level since August 7, as concerns over the yuan eclipsed data which showed monthly home prices up for a third straight month in July, indicating that country's all-important property sector may be finally bottoming.
Prior to the market open, the People's Bank of China (PBOC) set the midpoint rate at 6.3966 per dollar, firmer than the previous fix of 6.3969. However, the yuan fell against the greenback, slipping modestly to last change hands at 6.4011.
Among the mainland's other indexes, the blue-chip CSI300 and the smaller Shenzhen Composite plummeted 6.2 and 6.6 percent, respectively. Hong Kong's Hang Seng index tracked the losses in its mainland peers to move down 1.1 percent, touching a near six-week trough.
"With today's unsurprising yuan fixing, volatility in the [yuan] appears to have been put back in its box. However, the internal dynamics of China's economy continue to flash warnings that this calm will not last," Angus Nicholson, IG market analyst, wrote in a note.
Property counters were in focus; the country's largest residential property developer China Vanke inched down 0.2 percent in Hong Kong, but its Shenzhen-listed A-share plunged 3.7 percent. Hong Kong-listed China Overseas Land and China Resources Land lost 1.7 and 2.6 percent, respectively, while in Shanghai, Poly Real Estate and Gemdale erased gains to tank 8.3 and 6.5 percent, respectively.
Meanwhile, the utilities and industrial sectors were among the hardest-hit, with Jiangsu Linyang Electronics, Baoding Tianwei Baobian Electric and Jiangxi Ganyue Expressway losing the daily maximum allowable of 10 percent each. China Shipbuilding Industry and China Shenhua Energy also closed down 10 percent each, despite news that Beijing may be close to announcing broad plans to reform its state-owned enterprises (SOEs) this month.
Read MoreWeaker yuan a yawn for China's property market
SET slumps 2%
Thailand's benchmark SET index slid as much as 3 percent, after a deadly bomb explosion took place at one of the capital's most prominent shrines on Monday.
The tourism and leisure sub-index plunged 7.1 percent on the back of concerns that the latest attack could hurt the country's crucial tourism sector. According to newswires, Hong Kong's government has issued a "red alert" advisory against non-essential travel to Thailand.
Erawan Group —the operator of Bangkok's Grand Hyatt and the Marriott Courtyard hotels— skidded 9.2 percent, while other stocks with exposure to tourism such as Thai Airways and Airports of Thailand tumbled 5.5 and 6.6 percent, respectively.
Meanwhile, the Thai baht lost as much as 0.5 percent to 35.55 against the U.S. dollar - marking its lowest since April 2009.