Colombia's Farc warns over General Alzate's release

In a statement, the rebels complained of massive troop deployments in the northern province of Choco.

The government suspended peace talks it had been holding with the rebels in Cuba after Gen Alzate was captured.

The rebels said they had been planning to free the hostages on Tuesday.

Gen Alzate was captured along with two soldiers on 16 November.

On Saturday, President Juan Manuel Santos announced the Farc had agreed to release the hostages this week, without specifying the date.

But the rebels have now said that the handover will not go ahead in the current circumstances.

"The area has been taken over by the army, with troop deployments, aircraft over-flights and security measures that restrict the free movement of the communities who live there," says the statement, released by the Farc peace negotiating team in Havana.

"Unless the conditions change, it will be impossible to release Gen Alzate and his companions this week."

Handover details: Arturo Wallace, BBC News, Bogota

• President Juan Manuel Santos is likely to order the interruption of any military operations in a designated area for a short period of time, usually no more than 48 hours
• A delegation of the Red Cross travels to a previously agreed meeting point, probably by helicopter or by boat over the Atrato river
• ICRC conducts medically assessment of the captives on site
• ICRC will only confirm the men's freedom once they are inside its vehicles and on route to the place where they are handed over to the relevant authorities
• A more thorough medical examination and a debriefing will follow before the ex-captives can finally meet their families

No ceasefire

Gen Alzate and two soldiers were seized last Sunday when they was travelling by boat along the Atrato river in an isolated jungle region in Colombia's Pacific Coast.

The rebels said they took the action because they were unhappy at the continuation of Colombian military activities during peace talks.

Two more soldiers had been captured by Farc forces in Arauca a week earlier.

The Farc named the four hostages it planned to released this week as Ruben Alzate, Jorge Rodriguez, Cesar Rivera and Jonathan Diaz.

Since the peace talks began in Cuba two years ago, the Farc has called for a ceasefire to be declared.

But the government has refused, saying a truce would only help the rebels rearm and regroup.

An estimated 220,000 people have died in five decades of armed conflict in Colombia.