TAIPEI -- Taiwan's disease control department reported two new local dengue fever cases on Tuesday, bringing the total number of cases in the latest infection cluster to six.

The two newly confirmed cases are a man in his twenties and a woman in her seventies, both of whom reside in New Taipei City. According to the department, they began showing symptoms such as fever, headache, diarrhea, and vomiting between Sept. 19 and 20. The department added that both of them had visited high-risk areas related to previous confirmed cases.

This dengue fever infection cluster was first in northern Taiwan this year. All six confirmed cases have a history of activity in New Taipei City.

The island's environmental department warned Tuesday that recent heavy rainfalls on the island have resulted in water accumulation, and the week following such downpours is crucial for dengue fever prevention.

As of Monday, Taiwan reported 172 local dengue fever cases this year, eight of which occurred in the summer. It also recorded 213 imported cases, higher than the same period in the past four years.

Dengue is a mosquito-borne, potentially fatal disease that mainly affects people in tropical and subtropical regions, causing fever, nausea and muscle and joint aches.