MIAMI — Delta quietly added four daily flights from Seattle to San Jose (SJC), California over the weekend. The routes will be launch on September 2, 2014, utilizing two-class CRJ-900 regional jets. The move is the latest in the ongoing turf battle for Seattle.

The routes will connect the two tech heavy cities, both teaming with high yield passengers. Delta’s strategy for Seattle appears to be aimed at these high paying passengers and corporate accounts, particularly ones interested in connecting onward on the carriers new international routes. The carrier will have the opportunity to skim from Alaska Air and Southwest, both of which serve the route presently.

While the two carrier’s still play down the idea of an ongoing turf war, this recent move by Delta is being viewed by many as retaliatory. Alaska announced four new routes from its own top hubs and focus cities into Delta’s western stronghold of Salt Lake City (SLC) earlier in December. San Jose, for its part, is presently a major focus city for Alaska.

Separately, Delta added daily seasonal service to Juneau, Alaska today according to AirlineRoute. The service will begin on June 14th and continue through August 22nd utilizing Boeing 737-800 aircraft. Presently the Alaskan capital is served exclusively by Alaska Air, utilizing primarily Boeing 737-400 aircraft.

It is not Delta’s first foray into the remote city. It previously served Juneau years ago after having acquired Western, which had also served the city. Route maps list the city as late as 1994.

Delta has been slowly and carefully expanding operations into Alaska from Seattle. The carrier announced seasonal service to Fairbanks, and a second daily flight to Anchorage. Like Juneau, Delta served both through the mid 1990s. By the turn of the century, however, only Anchorage remained.