Some 2,000 Mexican federal troops used force last night to gain control over the Cananea copper mine. The federal police used tear gas and executed arrest warrants for union leaders of Section 65 of ICEM-affiliated Mexican National Miners’ and Metalworkers’ Union (SNTMMSRM) in northern Sonora state.

Mexican troops overtook striking miners at 20h00 on 6 June at the gates to the mine. Reports early this morning said that troops stormed Section 65’s union hall early on 7 June, also tossing tear gas that dispersed women and men present inside the building.

The ICEM today issued another letter to Mexican President Felipe Calderón, insisting that he “stop the violent actions taken yesterday and today by your government against trade union members and their families.” (The full letter can be seen here.)

It was the second time that the ICEM has sent a letter to Calderón urging him to use restraint in this volatile labour dispute. In February 2010, the ICEM and International Metalworkers’ Federation (IMF) cautioned Mexico against using force to break the strike.

The arrest warrants that arrived last night were for Section 65 Secretary-General Sergio Tolano Lizarrágo and Juan Gutiérrez Ballesteros, a National Executive Member of SNTMMSRM, or Los Mineros.

The Cananea copper mine, owned by Grupo México, has been shut since April 2007 when 1,200 miners began a strike over health and safety concerns and trade union rights.

The ICEM is calling on trade unions to send a similar letter to the Mexican government as the one linked above, or use the model letter here.