IMMIGRATION officers worked non-stop through the night to process applications from thousands striving to beat the deadline to become British Dependent Territories Citizens (BDTCs). And tempers flared into violence for the first time early yesterday, when a charge of queue-jumping drew several men into a scuffle which ended with four arrests. Immigration officers said late-comers could join the queue just seconds before tonight's midnight cutoff and still be assured their registrations would be accepted. 'Those who are in the queue before the stroke of midnight will have their applications processed,' said Immigration spokesman Eric Chan Kwok-ki. 'We decided to work overnight to do all the applications, so that no applicant is required to sleep overnight waiting for the doors to open,' another officer said. Staff initially planned to close counters at 8 pm, but this would have forced many to sleep on footpaths and at the muddy Wan Chai Sports Ground to reserve their spot. By midnight 21,745 applications had been received, giving yesterday by far the highest daily total so far. The previous highest count was Thursday, when 12,189 came forward. Yesterday afternoon, officials estimated 20,000 people had gathered in lines starting at Immigration Tower and flowing through footbridges and several office blocks before massing on the warm-up tracks and infield of the sports ground. A scuffle broke out about 9.30 am when three men aged from 31 and 39 were accused of queue-jumping by Leung Yan-kam, 60, who was standing in a nearby line. After being taunted, one member of the trio allegedly leapt over barricade tape. Mr Leung met him with an agility that caught the man off guard. The other two men then allegedly joined the fray and Mr Leung was repeatedly struck on the head with a heavy mobile phone. After being treated for head and hand injuries at Tang Shiu Kin Hospital, Mr Leung was taken to Wan Chai police station, where all four men were arrested and released on bail. More than 120,000 people have registered to become BDTCs this month, about 40,000 more than expected. Those whose registrations are approved can apply for a British National Overseas passport, which offers visa-free access to about 80 countries.