Emerging Asian equities returned to negative territory on Friday, led by South Korea, as higher oil prices rekindled inflation concerns and heavy artificial intelligence (AI) spending by US tech giants unsettled investors.

Sentiment soured after Alphabet and Tesla, the first of the "Magnificent Seven" to report this earnings season, highlighted hefty AI infrastructure spending that raised fresh questions over returns on such outlays.

South Korean shares bore the brunt of the regional sell-off, with the Kospi falling 5.7% by the close after three straight sessions of gains and ending the week 1.9% lower. AI memory maker SK Hynix and rival Samsung Electronics fell 8.3% and 7.4% respectively.