Andrea Mandell, USA TODAY; Salisbury Daily Times

Three Maryland residents tested positive Thursday for the coronavirus after traveling on an Egyptian cruise on the Nile River, Maryland Gov. Larry Hogan said on Friday evening.

The married couple in their 70s and an unrelated woman in her 50s, all from Montgomery County, are the first patients to test positive for coronavirus in the state.

"This does appear to be the same cruise ship the World Health Organization (WHO) announced today has 12 workers who have been placed in quarantine for 14 days" after testing positive, said Hogan. "And our three Maryland cases appear to be linked to six confirmed coronavirus cases in Texas."

On Thursday, Texas health departments announced positive coronavirus tests for several Harris County residents who had recently traveled abroad together.

Reuters reported Friday that the WHO and Egypt's health ministry said that the 12 Egypt cruise cases were diagnosed after a Taiwanese-American woman who had been on the cruise tested positive for the coronavirus upon her return home.

According to the state-owned online newspaper Al-Ahram Gate, the cruise ship had arrived in Luxor on Thursday after a two-day Nile voyage, passing by tourist sites such as the Kom Ombo temple and Edfu, Reuters reports.

The 12 patients will be transferred to an isolation facility and all others who had been in contact with them will be placed under a 14-day quarantine, according to the report. The ship was towed to an area 12 miles away from Luxor and placed under quarantine as well.

Although the three Maryland residents had flu-like symptoms after their trip, they were not tested for the virus for nearly two weeks, because the Centers for Disease Control and Prevention recommended tests only for people who had been traveling in China at the time of their return, Montgomery County Health Officer Travis Gayles said.

Hogan said two locations visited by the Maryland individuals visited after returning to the U.S. Feb. 20 were identified by the health department as possible risks for spread of the coronavirus.

One infected person attended a Philadelphia event in which schoolchildren and staff were present, according to the governor. As a result, Central Bucks County in Pennsylvania closed five local schools on Friday.

Another visited a public gathering at a retirement community in Rockville, Maryland, at which the person came in contact with about 70-to-100 people, including visitors, residents and staff, Hogan said.