OAKLAND, Calif. (KGO) -- Police arrested three juvenile teens accused of punching and trying to steal someone's cellphone on a platform at the Daly City station Sunday night.The three juveniles were taken to juvenile hall.Officials said this is at least the fourth cellphone robbery attempt on BART since April. On April 22, a group of more than 40 teens tried to take over a train car at the Oakland Coliseum station and robbed and beat passengers.Passengers are urged to be aware of their surroundings and to report any suspicious activity to BART police by calling 510-464-7000.for all crime reports submitted by BART.