Over 30 000 people fled the Nigerian town of Rann and across the border to Cameroon over the weekend amid fears of renewed attacks by Boko Haram jihadists, the UN said on Tuesday."All the population seems to be panicking and they are on the run as a preemptive measure to save their lives," UN refugee agency spokesman Babar Baloch told reporters in Geneva.Rann, near the border with Cameroon in northern Borno state, already saw an exodus of some 9,000 people earlier this month after a Boko Haram attack on January 14 left 14 people dead.Baloch said that Cameroon had sent back the 9 000 refugees and had initially sent in troops that are part of a multinational taskforce to protect the town."It was a bit peaceful, but as far as we understand now, that multinational taskforce has left," he said.Refugees had told aid workers that Boko Haram militants had "promised to return to Rann," he said, explaining the panic.He said UNHCR was reiterating its call to Cameroonian authorities "to keep the borders open, as we see thousands fleeing every day".* Sign up to News24's top Africa news in your inbox: SUBSCRIBE TO THE HELLO AFRICA NEWSLETTERFOLLOW News24 Africa on Twitter and Facebook. Baloch said that a recent upsurge in violence in northeastern Nigeria had already driven more than 80,000 civilians to seek refuge in already crowded camps or in towns in Borno State, "where they are surviving in tough living conditions."Rann, he said, had already been housing some 80,000 displaced people."The escalation in the conflict has thwarted people's intention of returning to their homes," he said, adding that some refugees who had attempted to return home from Cameroon had been displaced multiple times inside Nigeria or forced to become refugees again in Cameroon."The hostilities have strained humanitarian operations there and forced aid workers to pull out from some locations," he said.Jens Laerke, spokesman for the UN humanitarian agency, meanwhile told reporters that we have "260 aid workers who were withdrawn from three locations in Borno state" since early December.