JOHANNESBURG, Dec. 15 (Xinhua) -- Two hijackers were shot dead by South African police snipers following a 20-hour hostage drama outside Petrusburg in the Free State on Tuesday morning, the South African Press Association reported.

ER24 spokesman Lloyd Krause said the saga started around 10 a. m. on Monday, when a farm in the small town of Petrusburg was attacked.

"The farmer whose farm was under attack called his neighbors for assistance and the neighbors responded."

But the neighbors, a father and son, were hijacked by the attackers on their way to the farmhouse.

"The father and son duo is believed to have had a hunting rifle with them at the time of the hijacking," said Krause.

The hijackers sped off with them on Abrahamskraal road from Petrusburg toward Bloemfontein.

"The son managed to escape from the hijacked vehicle and managed to run to the Bainsvlei police station and summoned help."

A chase ensued when the police became involved and the hijacked vehicle came to a standstill on the road around 2 p. m., but the hijackers refused to hand themselves over.

"The police task force arrived on the scene at approximately 5 p. m.. Negotiations ceased at approximately 5 a. m. this morning [Tuesday] and resumed at approximately 6:10 a. m.. Food was delivered to the hijacked vehicle's occupants at approximately 9 p.m. last night."

Krause said at around 7 a. m. on Tuesday, the two hijackers were shot dead.

"Both of the hijackers were shot by police task force officers and are deceased. The sniper unit of the task force just neutralized them," said Krause.

The father was taken to hospital with minor injuries.

Beeld newspaper named him as Gerhard Venter and said he was the father-in-law -- and not father, as reported by the paramedics -- of Gerdus Venter, who was hijacked with him.

The Venters went to help Flip Kotze, of the Farm Uitvlug, who was held up and assaulted by two farm attackers.

But when the Venters arrived at the farm, according to Beeld, the two robbers were walking in the garden carrying big sports bags.

The two men told the Venters they were helping out on the farm, but the Venters ordered them to get into their bakkie.

But once inside the Venters' vehicle, the robbers held them up with a firearm that belonged to Kotze.

Gerhard Venter, in his 50s, then told Gerdus Venter to jump outof the bakkie. Two shots were fired at him as he did so, but he managed to get away.

Gerdus Venter, in his 30s, alerted the police who tracked down the bakkie and surrounded it, but the two men refused to hand over Venter.

That was when the negotiations started with them and the task force eventually arrived at the scene, after having their flight to Bloemfontein delayed twice due to bad weather.

At one stage, the wife of Gerhard Venter received an SMS from his phone, typed by one of the hijackers, which said: "We will have 2 [sic] kill him".

Police spokesman Senior Superintendent Vishnu Naidoo would not confirm the information released by the paramedics, saying the police would issue its own statement later in the day.