Gunmen have abducted two Chinese nationals from a construction site in southeast Nigeria, police said Friday.

The two were abducted by armed men wearing masks in Ohaozara in Ebonyi State on Thursday, police spokeswoman Loveth Odah said.

“The area was combed to track down the bandits but no result. A track down rescue team has been dispatched in order to rescue the Chinese nationals unhurt,” Odah added.

She made no comment on the motivation for the attack but kidnapping for ransom is common in Nigeria.

The victims are usually released after payment.

On Wednesday, four local emergency workers were abducted while returning from an assignment in oil-rich Rivers state.

Local media, citing family sources, said the kidnappers have demanded a ransom of 40 million naira ($112,000) for the four.

Many Chinese companies are engaged in multi-billion dollar infrastructure projects, including railways, airports and roads in Nigeria and their workers have often been targeted by kidnap gangs.