Workers at the southern seaport of Ashdod, Israel's main trade hub, went on strike on Friday following a dispute over the need to wear reflective safety vests, officials said.Tensions at the country's two largest state-controlled seaports, Ashdod and Haifa, have been high this year with the government trying to introduce privately-run piers.JPost.com staff contributed to this report.Nearly all Israel's exports and imports are transported by ship, making the port workers unions among the most powerful in the country. The unions oppose any new competition and have threatened to strike should the government or port management disrupt the status quo.The strike over vests came at the end of the work week, meaning it would have only a limited immediate economic impact.A row over a new directive that employees must start to wear reflective vests in certain areas led to the suspension of two members of the workers' committee, said a spokesman for the Histadrut, an umbrella union representing hundreds of thousands of public sector workers.The port union then declared a strike in protest at their suspensions, complaining of the "unrestrained" behavior of port chairman Gideon Siterman. The Histadrut spokesman said that unless a solution was found before Sunday morning, a labor court would discuss the issue then.The Histadrut called on the port's chairman to "restore sanity and restore work relations back to normal." The court could rule that the strike is allowed or that workers have to return to their jobs during negotiations."Any disruption in the ports hurts the economy, and a resolution needs to be reached," said Amir Hayek, head of the Manufacturers Association of Israel.