A recent surge in arrests and cocaine seizures in Peru points to an increased presence of Mexican drug cartels, counter-narcotics officials say. The cartels have also contributed to more drug-related violence in Peruvian cities, ports and in remote valleys in this Andean country where coca, cocaine's base material, is grown, the officials say. Peruvian claims of Mexican cartels expanding echo those by officials in other Latin American countries, from Honduras to Argentina, where Mexican gangs have supplanted once-powerful Colombian cartels as kings of the illicit-drug underworld. .... That Mexican drug lords are sending emissaries here is no surprise to Hidalgo...