According to Reuters, the indefinite strike is the largest in a string of protests to impact the Andean nation over the past year.

Colombia is in the midst of an economic slowdown.

Organizers said there were about 100,000 supporters of the rally, primarily from mining and agriculture.

Unlike other demonstrations, though, this one has been concentrated in distant highways and small towns, areas the group said were being ignored by the Colombian government.

Reuters said six main highways were blocked, and truckers parked their 18-wheelers in the middle of several highways. Twenty-two individuals were arrested Monday for causing disturbances.

“All the government cares about is attracting to Colombia the large, foreign mining companies and other multinational firms,” National Confederation of Colombian Miners executive director Luz Stella Ramírez said.

Coal and gold miners in the protest demand the country’s government abolish regulations that mandate all mines to be licensed regardless of size or location.

President Santos previously said the laws were needed to negate illegal, environmentally dangerous mines operated by leftist rebel groups and criminal gangs.

The protestors, however, feel the impetus behind the regulations is only to eliminate small mines and allow foreign operators to come in.

Santos has been urging workers to call off the strike. Last week, the frustrated leader called the group “useful idiots” manipulated by powerful political interests against him, the news service said.

Miners were the first to strike nearly a month ago, and were joined this week by those from other sectors of the Colombian economy including transportation and health workers.

Ramírez said the strike was probably the biggest for the mining industry in the country since the 1970s.