The search is on for a missing 23-year-old man visiting San Francisco from Los Angeles.
Paulo Netto, who moved to Southern California from Brazil in December, was in the Bay Area for the weekend.
His family in Brazil recently flew into the Bay Area and are on a frantic search for Netto.
Netto's sister, Ana Rodrigues, said she received a call from her brother Monday night.
Rodrigues said her brother sounded scared.
"Obviously he was terrified," she said. "He was saying Ana call the police I'm in trouble, people are following me."
Rodrigues called San Francisco Police and gave them the location of her brother's phone, 505 Shotwell.
She said police told her they found nothing there.
With no word from Netto, Rodrigues and her mother flew to San Francisco to search for Netto.
"We usually speak to him every day or two days," Rodrigues said of her brother's unusual silence and fear. "We also see him on the phone with Skype and Facetime."
The family filed a missing persons report with SFPD Thursday. They also went to the hostel where he stayed, checked hospitals and the bus station.
Netto had a bus ticket to go home to Los Angeles Sunday, but agents said it doesn't appear he got on the bus.
"He was a nice boy, not a trouble making boy," Rodrigues said. "He's really intelligent speaks four languages."