Police in southwest Nigeria on Sunday warned foreign nationals to be vigilant days after gunmen kidnapped two Indian workers in the region.
Gunmen seized the two men on Wednesday as they drove out of a pharmaceutical firm in Ibadan, the capital of Oyo state. They out the rear tyres of their vehicle to force it to stop.
State police spokesman Olugbenga Fadeyi said in a statement the force was making a "concerted effort" to find and rescue them, but did not say if the kidnappers had made contact with the families.
"All expatriates are advised to be vigilant and be watchful especially during this period," he said.
Security agencies should be alerted about "any suspicious movement around their facilities", he added.
Hundreds of Indian nationals live and work in Nigeria, especially in the pharmaceutical sector.
Kidnapping for ransom targeting foreigners and prominent Nigerians is common in Africa's most populous nation.
The victims are usually released unhurt after ransom payments, but the police rarely confirm any money was paid.
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