Building deeds might have to be amended to stop tenants hanging out clothes to dry on window frames - a possible cause for some falling frames, the director of the Buildings Department said yesterday. Wu Moon-hoi was speaking after two more aluminium window frames fell from public housing blocks in Kwai Chung and Yau Ma Tei yesterday. No one was injured. 'When there are winds, the pulling force of clothes on windows can be quite strong,' he said. But he said it would be difficult for the department to force tenants to stop the practice. He hoped the problem could be solved through discussion between property-management companies and tenants. 'The companies may [be able to] persuade tenants' not to hang clothes on windows, he said. 'For further action, we need to study the details of building deeds.' After yesterday's incidents, police arrested a 70-year-old woman from Hutchison estate in Kwai Chung and a 40-year-old man from the Kam Tong building in Yau Ma Tei. There were at least 28 cases of falling frames last month, raising concerns about laundry practices and building maintenance. Last week, a window frame fell on a car in Square Street, Central, shattering its windscreen and causing cuts to the driver's hands. Suen Kwok-lam, president of the Hong Kong Association of Property Management Companies, welcomed the Buildings Department's suggestion that deeds be amended to stop the hanging of laundry on windows. He said adding new conditions in building deeds could help clarify grey areas for laundry. Wong Kit-loong, director of property management at the Hong Kong Housing Society, said the society would be offering to examine aluminium windows in some old buildings without charge from tomorrow. The checks will be offered to residents of buildings more than 21 years old and with rates lower than $66,000. 'But owners will have to pay for the cost of repairing windows,' he said. For free window checks, call the Housing Society's hotline. The number is 31881188. A 76-year-old woman was taken to hospital yesterday after she was hit on the head by a plank while sitting in a park near Shek Lei estate in Tsuen Wan, RTHK reported. In another incident, a 52-year-old woman was hit by a piece of concrete inside a restaurant under renovation. She was treated for minor injuries.