EL PASO, Texas -- Singer-songwriter Fiona Apple was arrested for hashish possession at a West Texas Border Patrol checkpoint after a drug-sniffing dog detected marijuana in her tour bus.

Hudspeth County sheriff's office spokesman Rusty Fleming told the Associated Press on Thursday that Apple spent Wednesday night in the county jail in Sierra Blanca. Apple was released Thursday after posting bail.

Country singer Willie Nelson, rapper Snoop Dogg and actor Armand Hammer also have been arrested in Sierra Blanca on marijuana charges.

Fleming said that after the dog alerted the Border Patrol agent, the artist's bus was searched. Police found the drugs in a backpack -- about four grams of marijuana and a plastic bag with about four grams of a clay-like substance that tested positive for hashish were stored in a glass container, the sheriff's office said in a press release.

Apple admitted the drugs were hers, the release said.

The Sierra Blanca checkpoint inspects thousands of vehicles daily and sends the county thousands of drug cases yearly.

Apple "had a little tiny amount of pot and hash," Fleming said. While marijuana possession in small amounts is a misdemeanour, the Texas Controlled Substance Act says possession of hashish in any quantity is a felony.

Hashish is a drug prepared with the resin of the marijuana plant. It contains the same active ingredients as marijuana, but in much higher concentrations.

Apple's publicist, Ambrosia Healy, didn't immediately respond to an email request for comment.