A senior official at the University of California, Berkeley has apologised for causing confusion and anxiety among students and parents with a previous announcement that the university would ban students from Sars-infected areas. The apology came amid a call from the Centres of Diseases Control and Prevention in the United States for businesses and universities to continue with plans for meetings and events involving travellers from infected regions. Professor Donald McQuade, vice-chancellor for university relations, said he was sorry about the way the university had conveyed the message. 'If we have created difficulties and confusion, we sincerely apologise and we'll rectify that,' he said, while addressing senior officials of Chinese University. The US university this month banned students from Hong Kong, the mainland, Taiwan and Singapore from taking summer courses. But the ban was partially lifted shortly afterwards, and it will now allow about 80 students to go to Berkeley this month.