A man visiting from Los Angeles called his family to tell them he was being followed in San Francisco's Mission District on Monday and hasn't been heard from since, police said.
Paulo Netto called family in Brazil and a friend in Los Angeles and said he was in trouble and needed police assistance at about 11 p.m., police Officer Gordon Shyy said.
No one has heard from Netto since. Police checked phone records that indicate he was in the 500 block of Shotwell Street at that time.
His sister arrived in San Francisco and filed a missing person's report. Police have searched for him but he remains missing, Shyy said.
He is described as a 22-year-old man, about 6 feet tall and weighing 180 pounds with brown hair and brown eyes.
He speaks English and Portuguese and is believed to have been carrying a dark backpack and an iPhone 5.
Anyone with information about Netto's disappearance has been asked to call San Francisco police.
