Schools in the central Chinese city of Zhengzhou were closed on Thursday as heavy rains swept across Henan Province, prompting red alerts and transport disruptions, local authorities said.Non-boarding primary and secondary schools and kindergartens in Zhengzhou, capital of Henan, suspended classes on Thursday after the city launched its flood control emergency response. Residents were advised to avoid non-essential travel.As of Thursday morning, rains and waterlogging had forced dozens of highway toll stations in Henan to close or impose vehicle restrictions, transport authorities said.From Wednesday morning to Thursday morning, heavy rains swept much of Henan -- with downpours in parts of Xuchang, Zhoukou, Luohe and Nanyang.Provincial transport authorities have dispatched more than 10,000 personnel for flood control and rescue efforts.