The men, three Britons and a New Zealander, were captured by an armed gang early on Saturday in Grozny after a gunfight between the kidnappers and the men's bodyguards.
Their kidnapping comes just two weeks after British charity workers Jon James and Camilla Carr were released after spending 14 months as hostages in Chechnya.
The Foreign Office said last night that the companies employing the men - British Telecom and Granger Tele- communications - were regularly reminded of the official advice not to travel to Chechnya.
"We knew the men were there and we regularly warned them about the situation in Chechnya. Our travel advice which is not to go there," said the FCO, because of "the unstable security situation. There have been kidnappings ... recently."
While the FCO knew of the men's presence in Chechnya, the local security forces did not. The men were kidnapped just 500 metres from the headquarters of the newly-formed anti-kidnap unit, officers from which heard the shooting, but did not respond because gunfire is commonplace in Grozny.
"Despite the fact that the government of Britain did not recommend that its citizens visit Chechnya, these four came and did not inform anybody about their presence, not even law enforcement bodies," said Shadid Bargishev, head of the regional kidnapping department.
The men were named last night as Darren Hickey, 26, from Kingston-upon- Thames, Rudi Petschi, 42, from Cullompton, Devon, Peter Kennedy, 46, from London and Stan Shaw, a New Zealander living in Surrey. Mr Kennedy, a self-employed engineer, was contracted by BT while the other three worked for Granger Telecommunications.
None of the men's relatives were available for comment last night.
The Granger employees reportedly had been in Chechnya for 12 months while Mr Kennedy was on a 12-day contract. All the men were being paid ultimately by Chechnya Telecom to install satellite equipment as part of a new cellular phone system.
Reports emerging from Chechnya yesterday said the men were at home when as many as 20 armed men burst in at 4am. A gunfight took place between the kidnappers and the men's bodyguards. A number were injured and one of the kidnappers was in hospital being questioned by security forces.
Sources said last night that no ransom demands had yet been received and no-one had claimed responsibility for the kidnap.
It is exactly two weeks after Mr James and Ms Carr returned to Britain after being held by kidnappers for more than 14 months. Last night Ms Carr's sister, Alexandra Little, said: "My message to their families is not to give up hope. We are hoping and praying that they will be released much sooner than Jon and Camilla are."
The latest kidnapping is a stark reminder of the ease with which kidnappers operate in the republic, which has been reduced to near anarchy since the aftermath of its war with Russia in 1996. The Chechen authorities were blamed political opponents of Aslan Maskhadov's government for the kidnapping.Reuse content