The US has ordered more than a half of its personnel working at the US Embassy in Havana to return home. The order was accompanied by a travel alert, advising its citizens against visiting Cuba following what it called "specific attacks" on US personnel on the island, AP reports. The move comes a year after diplomats started reporting unexplained health problems that affected at least 21 embassy staff and their families. The Cuban foreign ministry called the move a “hasty reaction,” adding that Havana has nothing to do with the incidents and urged the US not to “politicize” the matter.