Two US Immigration and Customs Enforcement (ICE) special agents were shot in Mexico this afternoon.

The agents, who had been assigned to the ICE Attache office in Mexico City, were shot while driving between Mexico City and Monterrey by unknown assailants, ICE said in a statement.

In a separate statement, DHS Secretary Napolitano said that one agent was critically wounded in the attack and died from his injuries. The second agent was shot in the arm and leg and remains in stable condition.