Two Chinese construction workers were killed by gunmen in the town of Benisheikh in the northeastern Nigerian state of Borno on Wednesday, heightening fears that sectarian violence in the West African country will hamper development by discouraging foreign investment.

An official with the Chinese Civil Engineering Construction Corporation, or CCECC, told Agence France-Presse that the victims were driving into a worksite at 10:30 a.m. when the attackers moved in.

“Some unknown gunmen trailed them to the yard and opened fire,” he said, adding that the assailants then stole the company vehicle.

"This is the second attack on the yard by gunmen in just two weeks. Last month some gunmen attacked the same yard, killing two mobile policemen guarding the place," he said.

That brings the total death toll for Chinese nationals in Nigeria up to four over the past month alone.

Investigations into the Wednesday incident are ongoing. Boko Haram was an immediate suspect, but the group has not claimed responsibility for this attack.

Boko Haram, which was first formed in 2002 but has become increasingly militant since 2009, targets non-Muslims and moderate Muslims in northern Nigeria. Its goal is to implement a strict version of Shariah, or Islamic law, in the region.

Boko Haram and other insurgents have become a serious problem in Nigeria, killing more than 2,000 people in the past three years. The violence exacerbates tensions between Nigeria’s predominantly Christian south and its mostly Muslim north, where slow development and high rates of poverty breed widespread dissatisfaction with the government in Abuja, making it easier for insurgent militias to recruit new members.

Foreign investment may help to reverse these dangerous trends. Chinese investors have been increasingly attracted to Nigeria in recent years, something the federal government welcomes. The West African country’s vast oil wealth and huge demand for infrastructural development have spurred more than US$8 billion of Chinese investments in Nigeria so far. Trade between the two countries surpassed $10 billion last year.

Just this week, the CCECC opened up a brand new railway technology and construction institute in Abuja, with the goal of training local artisans and professionals and promoting home-grown development in the country.

But economic growth in Nigeria is stunted by rampant inequalities and governmental mismanagement of funds. The poverty rate is high, but hard to pin down since data is scarce; most analysts say it is more than 50 percent.

As long as these fundamental problems persist, the Nigerian government will be hard-pressed to put an end to insurgent violence -- and this can only dampen foreign interest in the country. Beijing officials have repeatedly called on Nigerian security forces to be more vigilant about protecting Chinese nationals.