According to Franco Mufinda, the 18 cases, all from Luanda, concern 14 male and four female people.
Eleven patients were also recovered, 10 from Kwanza Norte, he added.
Angola now has 705 confirmed cases, 18 more than on Saturday, including 29 deaths, 221 recovered and 455 active.
Among these, 15 people are in critical condition, under mechanical ventilation and three need hemodialysis.
Cases of covid-19 in Angola are concentrated in the range between 20 and 69 years of age, with a predominance of females, nine out of 10 being asymptomatic.
Serological tests (rapid tests) total 22,367 nationwide, of which 1036 are reactive, meaning that people have been exposed to the virus causing the disease and may still be in the active phase.
The covid-19 pandemic has already claimed more than 601,000 lives and infected more than 14.3 million people in 196 countries and territories, according to a report by the French agency AFP.
The disease is transmitted by a new coronavirus detected at the end of December in Wuhan, a city in central China.
In Africa, there are 14,937 confirmed deaths in more than 700,000 people infected in 54 countries, according to the latest pandemic statistics from that continent.
