U.S. inflation went up last month.

Gas prices rose quickly after more fighting in the Middle East.

The Labor Department said Friday that the consumer price index rose 3.4% compared with a year ago.

That is the same as July.

But prices jumped 0.4% from July.

That is four times the 0.1% increase the month before.

The report increases pressure on the Federal Reserve to raise its main interest rate next week.

That could raise mortgage and auto loan costs in the months ahead.

Fed Chair Kevin Warsh and other officials have said they need to see ongoing disinflation to leave rates where they are.

Kathy Bostjancic is chief economist at Nationwide.

She said the August report did not deliver that.

Gas prices rose 3.9% from July to August.

They are more than 27% higher than a year earlier.

Diesel prices have hit record highs above $6 a gallon.

This pushes up shipping costs for groceries and other goods.

Airline tickets rose 2.7% for the month.

They have soared more than 23% from a year earlier.

Hotel room prices climbed 2.4% from July to August.

Core prices exclude volatile food and energy.

They were 2.4% higher than a year ago.

That is down slightly from July's 2.5%.

But monthly core prices rose 0.3%.

That is the largest increase since April.

Wall Street investors now see a more than 80% chance the Fed will raise rates Sept. 16.

This is according to CME Fedwatch.