Colombia worked Friday to free five hostages whose capture by the leftist FARC guerrillas has derailed peace talks, but kept the highly anticipated handover shrouded in secrecy.

There was no sign that military activity had been halted in either of the regions where the hostages were captured, a precondition for the handover.

The highly anticipated handover of a general and four other hostages captured by FARC guerrillas got underway Thursday, Colombian President Juan Manuel Santos said, paving the way for the resumption of peace talks.

"The procedure is underway," said the president, referring to the release of General Ruben Alzate and four other army captives being held by the Revolutionary Armed Forces of Colombia.

Colombian police arrested 11 gang members suspected of using human mules to smuggle narcotics to Asia, charging four of them with murder after a courier died of a cocaine overdose, officials said Wednesday.

Authorities said capsules of narcotics were ingested or strapped to the bodies of the mules who were sent to Hong Kong, China, Singapore and Thailand.

The Colombian government and the FARC struck a deal Wednesday to free "as soon as possible" a general and several others the guerrillas are holding captive, suggesting the faltering peace process is back on track.

Some 1,500 troops, 10 helicopters and planes, as well as boats and land vehicles, have been scouring the Choco region for General Ruben Alzate, the highest-ranking military officer to be kidnapped by the Revolutionary Armed Forces of Colombia in five decades of conflict.

The Colombian army has mounted a massive search for a general captured by FARC guerrillas, a kidnapping that has derailed peace talks just as they marked their two-year anniversary Wednesday.

Some 1,500 troops, 10 helicopters and planes, as well as boats and land vehicles have been deployed in the jungle-covered region of Choco to search for General Ruben Alzate, the highest-ranking military officer to be captured by the leftist Revolutionary Armed Forces of Colombia in five decades of conflict.

Colombia's FARC guerrillas confirmed Tuesday that they are holding a missing general whose kidnapping caused the government to suspend peace talks aimed at ending the country's 50-year-old conflict.

In a statement datelined from the Colombian mountains and published on the FARC website, the leftist rebels' Ivan Rios unit said it had captured General Ruben Alzate, Corporal Jorge Rodriguez and army adviser Gloria Urrego, who disappeared Sunday in the remote department of Choco.

The fate of peace talks is in the hands of the FARC rebels, the Colombian president warned Monday, after halting the negotiations designed to end Latin America's longest-running conflict. 

The Marxist guerrillas are under increasing pressure at home and internationally to free a general whose kidnapping prompted President Juan Manuel Santos to stop the talks, throwing the two-year-old negotiations into fresh crisis.

The EU on Monday urged Colombian rebel group the FARC to "immediately and unconditionally" free a general and two others the movement is suspected of having abducted, causing the suspension of peace talks.

General Ruben Alzate, an army corporal and a lawyer went missing Sunday in an area where leftist FARC rebels are active, with suspected responsibility for the incident widely falling on the group.

Colombian President Juan Manuel Santos on Sunday suspended peace talks with the country's largest rebel group, the FARC, as the military investigates the suspected abduction of a general.

"Negotiations with #FARC are suspended until the facts of the kidnapping of general (Ruben) Alzate are clarified," the Ministry of Defense said in a tweet citing Santos.

FARC rebels kidnapped two Colombian soldiers after clashes between the Marxist guerrillas and the military in the far east of the country, the army said Thursday.

The capture, which comes amid a slow-moving peace process between the rebels and the government, took place in Arauca Department, bordering Venezuela, the National Army of Colombia said in a statement.