MONROVIA, Liberia (AP) — Authorities have closed a portion of Liberia's northern border with Guinea and plan to expand the cordon amid a resurgence of Ebola.

Liberian Information Minister Eugene Nagbe confirmed Tuesday that the closure is in effect in Lofa County, and officials intend to shut down the rest of the border with Guinea.

Guinea had been on track to be free of Ebola transmission this month but then two new cases emerged.

The new outbreak has prompted fear in Liberia, which has lost more than 4,000 people to the deadly virus and already has been declared Ebola-free twice only to find more cases.

Critics warn the border between the two West African countries is porous and people will continue to enter Liberia in forested areas because of cross-border business.