Guatemalan police claim to have killed two members of a violent Mexican drug cartel believed to be responsible for a mass killing that left 27 people dead over the weekend. Guatemalan authorities say a third member of the cartel, known as Los Zetas, was arrested. Meanwhile, Guatemalan President Álvaro Colom has declared a state of siege in the northern region of the country that will last until at least Tuesday as authorities search for more suspects. Police have been granted the right to conduct night raids and carry out arrests and searches without warrants and also curtail rights of expression and assembly.