The cases involved two males and two females, all occurring in Luanda, the capital, the minister told a press conference Thursday evening.

He said none of the patients have died among the cases and that no new contact cases have been reported.

The Ministry of Health has strengthened the epidemiological and laboratory surveillance of suspected flu cases in sentinel health units to monitor the epidemiological development in the country and provide necessary responsive measures to prevent H1N1 spread, the minister said.

He noted that the epidemiological surveillance system has observed an increase in cases of seasonal flu since April, and in addition to H1N1 cases, there have also been registered cases of rhinovirus flu.

(With UNI inputs)