The Colombian president, Andres Pastrana, has declared his country's three-year-old peace process over and vowed to retake the jungle territory he had granted to rebels as a site for talks.

Mr Pastrana made the announcement in a televised address last night, hours after guerrillas hijacked an airliner and kidnapped Senator Jorge Gechen Turbay, president of the Colombian Senate's peace commission, who was travelling on the flight. The remaining 29 passengers and crew were freed unharmed.

"Today the glass of indignation spilled over," Mr Pastrana said. Calling the hijacking "an international offence classified as terrorism" he added: "It's not possible to sign agreements on one side while putting guns to the heads of innocent people on the other."