Peru has declared a 60-day state of emergency on its border with Colombia in order to guarantee security in a region rife with drug trafficking.
President Martin Vizcarra on Monday said the measure was "because there are security problems" created by Colombian citizens crossing the border and there was a need to "reestablish the state's presence."
Police and armed forces used five helicopters and three planes in joint operations with their Colombian counterparts in the first patrol in the area, Vizcarra said.
"More than 50 people were arrested, most of them Colombians involved in illicit drug trafficking," he said.
The region in which the state of emergency has been declared is the Amazon basin province of Putumayo, separated from Colombia by the river of the same name, a tributary of the Amazon.
"We're firm, we're clear, we're going to defend our sovereignty and our territory," added Vizcarra.