TAIPEI — Taiwan's air force on Wednesday warned off Chinese warplanes that approached the country, the defense ministry said, reporting the fourth such intrusion in just nine days.

The Chinese J-10, a fighter jet, and Y-8, a turboprop surveillance aircraft, entered Taiwan's air defence identification zone to the southwest of the country on Wednesday.

Taiwanese fighter planes issued a verbal warning to the Chinese aircraft to leave and the Chinese planes "immediately left" the air defence identification zone, the ministry said.

The latest incursion comes after a J-10 fighter entered Taiwan's air defence identification zone from the southwest on Tuesday.

On Friday, a Chinese Y-8 was issued a verbal warning by Taiwan's air force to leave its air space in the same area.

The Y-8 flight came only a few hours after Taiwan announced it had conducted missile tests at two locations off its eastern coast.