Updated

Branches of Tunisia's main labor union have called for general strikes in four provinces in the country in response to an attack on its members in the capital by supporters of the Islamist-led government.

The move Wednesday is the latest escalation in the confrontation between the union and the ruling Islamist Ennahda party.

The union called for a general strike on Thursday in Sfax, the country's economic capital, Gafsa, the center of phosphate production, and in Sidi Bouzid and Kasserine, where the uprising that overthrew Tunisia's longtime dictator last year began.

Last week, a general strike in the province of Siliana degenerated into five days of clashes with police. On Tuesday, government supporters attacked union members at their headquarters in Tunis.