MEXICO CITY: US authorities announced plans to seek the extradition of Mexico's most powerful drug lord after his capture in a US-backed operation that included a drone, cellphone intercepts and elite Mexican marines.

As prosecutors in New York prepared their request, new details emerged Sunday from the manhunt that led to the capture of Sinaloa cartel boss Joaquin “El Chapo” Guzman, whose empire has smuggled drugs to the United States, Europe and Asia.

The US surveillance drone was used for two weeks between mid-January and mid-February to back up a massive operation in the northwestern city of Culiacan, a US government official told AFP on condition of anonymity.

Guzman eventually slipped out of Culiacan, the capital of Sinaloa state, after escaping through tunnels under one of his safe houses as the marines closed in on him, Mexican and US officials said.

Under pressure, the 56-year-old drug capo, who had been on the run since escaping from prison 13 years ago, fled further south to the beach resort city of Mazatlan.

It was there that the elite marine unit captured him on Saturday, in the fourth floor of a condominium, with a surprisingly small entourage that included one lookout, one bodyguard and a woman believed to be his beauty-queen wife, the US official said.

Guzman went down without a single shot.

“Cellular telephone intercepts were involved in the arrest,” the official said.

The US Drug Enforcement Administration had provided intelligence information to the marines.

The US official said the remote-controlled aircraft was not used in Mazatlan, but it had been deployed in Culiacan to corroborate other intelligence and that Mexico's military had authorized its use.

One of the world's most wanted man, Guzman had been spending most of his time in the bustling city of Culiacan, living in houses with escape tunnels, extra thick walls and steel-reinforced doors, officials said.

“It's a big city where he has his contacts, his women, his houses,” the US official said.

Officials had hoped that Guzman would flee to a rural, more open space to capture him, and his decision to run to Mazatlan around three days before his arrest was a surprise, the official said.

His arrest capped a months-long operation that resulted in the arrests of a dozen Sinaloa cartel operatives, including alleged bodyguards of Guzman's top associate, Ismael “El Mayo” Zambada.

Several cellphones were seized from the detainees and later used to establish wiretaps as part of the operation against the Sinaloa cartel, said an official from the Mexican attorney general's office.

The official said authorities are still searching for Zambada, who is considered Guzman's natural successor.

US seeks extradition

Nabbing Guzman, who is considered the world's biggest drug trafficker, was a major victory in President Enrique Pena Nieto's push to rein in drug violence in his country.

The Sinaloa cartel's turf wars with rival gangs contributed to a wave of drug violence that left more than 77,000 people dead in the past seven years.

The United States had offered a $5 million reward for information leading to his capture, with several indictments in cities from New York to San Diego.

Robert Nardoza, a spokesman for the US Attorney's Office for the Eastern District of New York, said prosecutors there “plan to seek his extradition.”

A senior Republican lawmaker called for Guzman's extradition, warning that “the biggest fish ever” may try to flee again in a repeat of his legendary 2001 escape from prison in a laundry cart.

“I think that would be the best course for not only Mexico, but also the United States, in ensuring that what happened in 2001 does not happen again,”Michael McCaul, chairman of the House Homeland Security Committee, told ABC television.

A Mexican foreign ministry spokesman declined to comment on the planned extradition request.

An official in the Mexican attorney general's office said Guzman has to finish the 20-year sentence he avoided by fleeing eight years into his prison term.

But he is also facing new charges of drug trafficking, using illegal funds, organized crime and possession of weapons reserved for the military, the official said.

The captured kingpin is not facing murder charges.