The roofs of nine flats at Jalan PBS 14/7 of the Bukit Serdang Industrial Area near here were damaged in a thunderstorm on Wednesday.

Selangor Fire and Rescue assistant director Mohd Sani Harul said the department was informed of the storm at 5.17pm, following which two engines from the Serdang and Bangi stations, with 14 members, rushed to the scene.

"The storm caused damaged to the roofs of nine flats, with some parts ripped off," he said when contacted by Bernama.

However, he said, no casualties were reported.

The storm also caused massive traffic jams and trees to fall around the Klang Valley.

A Malaysian Highway Authority sopkesman said KM8.7 of the Besraya Highway in the direction of Kampung Malaysia and Sungai Besi was clogged with traffic because flash floods forced the closure of one lane.

"The water ebbed about two hours later," he said.

A city traffic police spokesman said it was the same along Jalan Sultan Ismail and Jalan Raja Chulan but traffic was not gridlocked.

Meanwhile, a city Fire and Rescue Department spokesman said trees were uprooted in Taman Ibu Kota, Gombak; Jalan Klang Lama and Bandar Tun Razak, Cheras.

Plus Malaysia Berhad (PLUS) in its Twitter site reported that traffic jams were worse than normal rush hour snarls on the North Klang Valley Expressway from Damansara to Dataran Prima; Jalan Duta to Bukit Lanjan, Puchong; Kelana Jaya and Damansara Utama as well as from Bandar Utama to SS2.