KUALA LUMPUR -- Malaysia's central state of Selangor has been put on dengue alert after the mosquito-borne disease killed three people within a week, DPA quoted news reports as saying Saturday.

Selangor joined six other states, including the capital Kuala Lumpur, on dengue alert after the number of cases there grew to 6,000, a 30 percent increase.

"The state government views the situation as critical, considering there had only been seven deaths until September 29 this year," State Health Committee Chairman Tang See Hang said.

"The present situation is also bad as there were only three deaths for the whole of last year," he told the Star newspaper.

Tang said the disease, which has claimed about 50 lives nationwide this year, had to be viewed seriously and urged the public to take measures to keep their surroundings clean to root out the breeding grounds of the aedes mosquito, which spreads the disease.

Characterized by painful joints, fever and a rash, dengue symptoms usually begin within a week of a mosquito bite and last for seven days.