Preliminary evidence shows that two cases of the more contagious South African coronavirus variant have been identified in Montgomery County, according to officials.

Health officer Travis Gayles on Tuesday told members of the Montgomery County Council that officials received a report on Monday of two residents that received a “preliminary positive result” for the South African variant.

“I will caution, we have very limited information,” Gayles said of the early evidence.

County officials are awaiting further information, but Gayles said it is “suggested” that the cases are tied to travel and not community transmission. On Tuesday, Gov. Larry Hogan confirmed the cases, and said “contact tracing is underway, and close contacts are isolating.”

Montgomery County’s cases mark the latest instance of variant spread across the D.C. region. Maryland identified its first case of the South African variant on Saturday, involving a Baltimore-area resident who had not travelled, “making community transmission likely,” according to Maryland Gov. Larry Hogan. In mid-January, the state’s first two cases of the U.K. variant were reported in Anne Arundel County.

The U.K. strain was also identified in Northern Virginia in late January.

Both the U.K. and South African strains are believed to be more contagious than other strains of the virus, but have not shown to increase the severity of the illness. Early studies indicate that the variants only slightly impact the effectiveness of the Moderna and Pfizer vaccines.