LA MESA, Calif. -- Thieves who had just robbed an East County bank dumped their loot onto the street Thursday after a hidden anti-theft dye pack exploded, and several passers-by were detained for trying to make off with some of the ink-stained bills.

The trio of bandits entered Torrey Pines Bank on Center Drive in La Mesa shortly about 10:15 a.m., pulled pistols and demanded money, police Capt. Ed Aceves said.

They took currency from a teller, then ordered a manager to give them more cash from a safe, Aceves said.

The robbers then left the bank, got into a tan sedan and sped off to the east. A short distance away, they tossed out a bank bag holding most of the stolen cash and continued fleeing, getting onto nearby Interstate 8.

Patrol officers arrived to find two vehicles stopped on Center Drive near the dumped sack of money, according to Aceves. They detained the three occupants and found some of the stolen bills in the cars.

"It was determined that these subjects were not involved in the robbery, but they stopped to pick up the cash that they saw in the street," the captain said.

Officers arrested the three on suspicion of misappropriating found property.

The robbers remained at large Thursday afternoon.