U.S. consumer prices jumped by the most in nearly 9 years in March.

The Labor Department reported Tuesday that the consumer price index rose 0.6%. That was higher than economists had expected.

Fueling that increase: a 9% rise in prices at the pump. Gasoline accounted for nearly half of the index’s increase.

But stripping away the volatile food and energy components leaves consumer prices with a 0.3% rise. Higher rents and vehicle insurance costs drove up the so-called core CPI.

The huge government fiscal stimulus package and sharp rise in vaccinations have kicked off what most economists expect will be a brief period of higher inflation. Federal Reserve Chair Jerome Powell also sees the price hikes as transitory.

The rise in consumer prices comes on the heels of a government report showing a big surge in prices at the wholesale level.

Fractured supply chains, the relief package, and low interest rates are seen as igniting price pressures. But slack in the labor market could make it harder for companies to pass the higher costs on to consumers.