According to Thursday data from comScore, Yahoo captured 17.4 percent of the U.S. search market in August to land in the number two spot behind Google; a report that conflicts with Tuesday data from Nielsen that put Microsoft's Bing ahead of Yahoo.

Last month, Yahoo had 17.4 percent of the explicit core search market, an increase of 0.3 percent from July, comScore said. Bing, meanwhile, had 11 percent of the market, an increase of 0.1 percent. Google continued its dominance with 65.8 percent of the search market, though that was down 0.4 percent from the previous month.

ComScore excluded contextually driven searches, as did Nielsen.

On Tuesday, Nielsen reported that Bing surpassed Yahoo for the first time to become the number two search engine in the U.S. Bing nabbed 13.9 percent of searches, up 2 percent from the previous month and up 30 percent from the same time period last year. Yahoo had 13.1 percent of searches in August, down 8 percent from July and down 18 percent from last year, Nielsen said.

Overall, nearly 15.7 billion core searches were conducted in August, comScore said. Google ranked number one with 10.3 billion searches, followed by Yahoo with 2.7 billion - a 3 percent increase - and Bing with 1.7 billion, up 2 percent. Rounding out the top five were Ask and AOL.

In terms of core U.S. searches - which does not include searches on mapping, directory, or video sites - Google still came in at number one with 60.5 percent of the market, down 1.1 percent. Yahoo was number two with 20.1 percent and Bing at number three with 12.6 percent, an increase of 0.9 percent and 0.2 percent, respectively.