Johannesburg - A group of striking MTN workers on Friday blocked 14th Avenue in Fairlands, north of Johannesburg, said metro police.The workers were demanding bigger bonuses and annual salary increases. Chief Superintendent Wayne Minnaar said: "The road is not safe to use. It is blocked."He urged motorists to avoid the area."The group is waving placards and dancing in the street," said Minnaar.MTN's workers, affiliated to the Communication Workers Union, have been striking since May 20.Earlier this week, MTN's South African operations CEO, Ahmad Farroukh, resigned.His resignation is effective as of July 31 2015.“This was a difficult decision to take for Ahmad, but unavoidable due to personal and family reasons,” said MTN group president and chief executive officer Sifiso Dabengwa.Farroukh's exit from MTN, which is Africa's biggest mobile network, also signals how the telecommunications company is struggling to cement a CEO for its South African operations.It was only in August last year when Farroukh replaced former SA CEO Zunaid Bulbulia.At the time, MTN said the hiring of Farroukh as its South African unit's CEO was in line with a management rotation policy at the company.