Efforts to secure the release of an Aberdeen-based firm's workers who were kidnapped in Nigeria are continuing amid reports of a £21m ransom demand.
Hostages are often released after a few days of captivity
Three men from Sparrows Offshore were among those kidnapped at gunpoint on Tuesday.
There are unconfirmed reports that the kidnappers have demanded £5.3m for each of four British workers taken.
The Foreign and Commonwealth Office (FCO) said contact had been made with the captives, who were "okay".
Further contact between FCO sources in Nigeria and the kidnappers was expected on Friday.
A spokesman for the FCO said: "Intensive efforts are being made to secure the release of the workers."
One of the kidnapped workers has been named as engineer Paul Smith, from Peterhead.
There has been a wave of kidnappings of oil workers by militants in the country seeking ransoms. Victims are often released a few days after being taken.
The FCO is advising against all but essential travel to the area.