Asian shares fell on Thursday after a mixed start, amid uncertainty over the U.K.'s exit from the European Union and as the dollar strengthened.

Japan's fell 0.8 percent or 154.3 points to end at 19,063.22, likely due to prolonged yen strength. The yen is seen as a safe-haven currency, but a stronger yen is generally negative for many Japanese companies as export earnings are reduced.

Shares of Toshiba surged 4.01 percent, after its shareholders approved a proposal to split off the Japanese conglomerate's NAND flash memory unit, amid growing losses at its U.S. nuclear subsidiary, Westinghouse Electric.

Westinghouse filed for bankruptcy on Wednesday, after it posted a multi-billion dollar write-off due to cost overruns at four nuclear reactors under construction in the U.S.

The ASX 200 closed up 0.39 percent or 22.7 points at 5,896.2, led by its materials and energy sub-indexes.

Earlier, official data showed that job vacancies have risen 1.8 percent to 182,400 from the previous quarter. This was the highest number of job vacancies since May 2011, and seen as a positive for Australia's labor market.

Australia began evacuating thousands of people from resort islands in the tropical northeast on Thursday, as water supplies began to run low, Reuters reported. On the mainland of Queensland, tens of thousands of people were still without power, as officials warned of more heavy rainfall in the wake of Cyclone Debbie.

In South Korea, the Kospi index slipped 0.11 percent or 2.3 points to close at 2,164.64.

Samsung Electronics, which released its Samsung Galaxy S8 smartphone in South Korea today, was up 0.48 percent. The latest model is the company's first premium smartphone since its September recall of all Galaxy Note 7 devices due to its fire-prone batteries.

The dropped 1.0 percent or 32.4 points to finish at 3,208.93 and Shenzhen composite closed 1.97 percent or 39.8 points at 1,979.58. Hong Kong's index was down 0.32 percent by mid-afternoon.