Cuba's state-run telecommunications monopoly ETECSA on Monday provided free internet trials for mobile phone users for the first time but the official start date of the service remains unknown.

The trial served to "check the operation" and "assess the capabilities" of the 3G network infrastructure in the Caribbean country as "part of the preparatory actions for the start of Internet service through mobile phones," ETECSA told state news agency ACN.

The telecom operator conducted the internet trial without prior notice, surprising mobile and tablet users in Cuba who had never before been able to access the internet on their devices.

ETECSA carried out the free internet trial for several hours and announced that "if necessary, other tests will be carried out in the following days".

The company, however, did not specify when the service will be officially available as the start date, "as well as the rates and other details of interest will be informed through the media and official channels of the company."

Internet service for mobile phones in Cuba is currently only available for foreign companies, but ETECSA said last July that "the technological infrastructure for the commercialization (of this service to individuals) is almost ready."

The trial caused some congestion in the output of text messages and call reception in the Cuban mobile phone network, noted EFE journalists.

Free, fast and cheap internet service is an ongoing issue for Cuba, where the government has for several years been promoting a "policy of computerization of society".

ETECSA launched several public Wi-Fi hotspots in July 2015, totaling more than 630 spots nationwide. Internet commercialization began in 2017, but it was only allowed to a small professional sector.

Despite nationwide enthusiasm about the country's first ever Wi-Fi service, complaints arose concerning the lack of internet-available sites and the initial connection fees of $2.5 per hour, which gradually decreased to $1 as of Monday.

In the case of the home internet service known as Nauta Hogar, the prices range between $15 and $70, depending on the speed, for 30 hours a month.

Both services are expensive for Cubans, whose average salary is below $30 a month.

According to the latest official data, Cuba, which has a population of 11.1 million, registered more than 4.5 million Internet users in 2016, averaging 403 users per 1,000 people in the country.

A decade ago Cubans were not allowed to have a mobile phone registered under their name. However, earlier in June, there were more than 5.2 million active mobile lines in the country.

Nearly 2 million lines were cut off in four provinces after a fire damaged the telecommunications infrastructure of the central province of Villa Clara on Jun. 25.

The incident delayed the works of 3G technology in the center and west of the country.