Johannesburg - Truck drivers are an essential element of South Africa's economy - yet are paid "pitifully" low wages, the Congress of SA Trade Unions (Cosatu) said on Tuesday."Truck drivers work for long and unsocial hours, battle with difficult road conditions, require a high degree of skill and are an essential cog in the wheels of our economy," spokesperson Patrick Craven said in a statement."Yet they are rewarded with pitifully low wages."Cosatu supported truck drivers' demand of a 12% inflation-related pay increase.Over 20 000 road freight employees embarked on a protected strike on Monday.Craven said some employers were trying to divide workers by alleging that the strike had been averted."Cosatu calls upon the employers to return as soon as possible to the negotiation table with an improved offer, failing which the federation will continue to give support and solidarity to the strikers."Earlier on Tuesday, striking workers in Gauteng rejected their employers' latest offer of 8.5%, said SA Transport and Allied Workers Union (Satawu) spokesperson Vincent Masoga.However, talks continued at the Commission for Conciliation Mediation and Arbitration (CCMA) in Johannesburg on Tuesday afternoon.Unions of the remaining provinces and employers continued discussing the offer.Striking truck drivers in the Johannesburg CBD threw stones at passing trucks earlier on Tuesday.Chief Superintendent Wayne Minnaar advised companies not to send any trucks into the Johannesburg CBD in order to avoid further violence and damage to trucks.* Follow Fin24 on Twitter, Facebook, Google+ and Pinterest.