Muslim leaders are calling for urgent talks with the premier to discuss security concerns, as police confirm an investigation is underway into a second "threatening letter" sent to a Sydney mosque. The letter was sent to Lakemba Mosque in Sydney's south-west on Wednesday afternoon. A police spokesperson said it "has been seized by detectives and will undergo forensic examination". Mosque spokesperson and secretary of the Lebanese Muslim Association Gamel Kheir forwarded a copy of the letter to the ABC. He said the note depicted a handmade drawing "of a mosque that's on fire with people, parishioners within, inside the mosque,...