BEIJING, Sept. 18 (Xinhua) -- Typhoon Wipha forced eight cities and counties in northern Taiwan including Taipei to close schools and offices Tuesday.

Taipei Stock Exchange also closed as the city stopped work, local media reported.

Songshan Airport, Taipei, closed at 9:00 a.m. and all flights were cancelled. United Airlines delayed its flight from Taipei to San Francisco to 3:00 p.m., at least three hours later than scheduled. Hong Kong's Dragoair canceled two flights, the airlines said on its website.

Taiwan Electricity Co. said 688 households had lost their power supply.

Wipha is heading northwest at a speed of 17 kilometers per hour and is approaching Shanghai and the coastal provinces of Zhejiang and Fujian.

The local meteorological authority estimated the strongest winds would hit Taiwan today and issued both sea and land warnings.

It also forecast rainfall in the northern mountainous region of Taiwan might reach 500 to 700 millimeters.

At 4:00 a.m., the center of typhoon Wipha was located off east Taiwan, about 260 kilometers from Yilan, according to the local meteorological observatory.

Wipha, given a woman's name in Thai, is the 13th tropical storm this year.