Car service app Lyft stepped up its competition with longtime foe Uber over the weekend. The company slashed the price for a carpooling trip below 97th Street in Manhattan to $5 on Friday -- following Uber cutting its prices to $10 south of 96th Street for its ridesharing service earlier that day.

The Manhattan fare war between Lyft and Uber comes as the City Council considers fighting congestion with a cap on black and livery cars.

About 25,000 such cars have been added since 2011, when Uber launched in New York City. Lyft came into the market in July 2014. Both apps launched their carpool services in New York City in December last year.

"It's core to our mission to reconnect people and communities through transportation," said David Mack, Lyft's director of public affairs, in a statement. "We spend a lot of time trying to make sure every Lyft you take is a great experience, but we also know price matters."

The company says if it can't find a matching passenger on the carpool service, called the Lyft Line, the price is the same. Additional passengers in the same group will also pay an extra buck.