Taiwan says Chinese computer hackers have expanded the scope of their attacks from gathering military intelligence to stealing business secrets from the island's high-tech companies.

Tsai Teh-sheng of the island's primary intelligence agency said late Wednesday that Taiwan has created a shield to protect government offices from "severe" Chinese cyberattacks.

But he pointed out that Chinese hackers are able to sabotage privately controlled infrastructural networks, including those belonging to banks and transportation companies.

Despite Tsai's warnings, analysts say Chinese hackers are unlikely to attack Taiwanese interests amid the rapidly warming relations between the sides.