Canadian mining company Agnico Eagle said on Wednesday that a group of armed men stormed one of its mines in northern Mexico early on Tuesday morning, injuring a security guard and making off with a haul of silver and gold. Agnico Sonora, the company's Mexican subsidiary, did not provide an estimate of the value of the theft, but said the La India mine, in the northwestern state of Sonora, was operating normally, with soldiers and police conducti…