ABC News' Carol McKinley and Clayton Sandell report:

Colorado authorities Wednesday issued a "be on the lookout" alert for two gang members associated with Evan Ebel, the man authorities believe gunned down a Denver pizza delivery driver and the head of Colorado's corrections system.

The men are James Franklin Lohr, 47, and Thomas James Guolee, 31. Both are considered armed and dangerous and are known associates of the 211 Crew, a white supremacist prison gang, El Paso County Sheriff's Lt. Jeff Kramer told ABC News late Wednesday night.

Ebel was also a member of the 211 Crew who was released from prison in January. He is suspected of murdering Domino's pizza driver Nathan Leon on March 17, and Colorado prisons chief Tom Clements on March 19. Ebel was killed March 21 during a shootout with authorities in Texas.

Colorado Department of Correction/AP Photo

According to two law enforcement sources who are not allowed to speak publicly about the investigation, Lohr and Guolee are wanted because authorities believe they were in "frequent contact" with Ebel by phone, including just 24-48 hours before Clements was gunned down at the front door of his home in Monument, Colo.

According to an alert broadcast to police officers Wednesday night, Goulee was last seen in Colorado Springs and Lohr may have fled to Texas or Nevada.

Lohr and Guolee have extensive criminal records, according to court documents.

On Tuesday authorities revealed that Ebel- who was on parole- was outfitted with an electronic ankle bracelet meant to help keep track of his whereabouts. The bracelet stopped working three days before Leon was killed, but a parole officer did not attempt to locate Ebel at his home until March 19, the same day Clements was murdered.