ACCRA, Jan. 23 (Xinhua) -- At least six people were shot dead and seven others wounded by a group of unknown gunmen on a bus in Ghana's Upper East Region, an official confirmed to Xinhua Tuesday.

       The victims came under attack Monday while traveling from Bawku, an urban community in the Upper East Region, to a market center in a nearby community, said Hamza Amadu, municipal chief executive for Bawku.

       Amadu said the dead included two men and four women, and the wounded are receiving treatment at two nearby hospitals.

       "Security has been beefed up with military and police patrols, while a curfew is also in place to control movements at night," the official said.

       A combined police-military operation is underway to identify and arrest the perpetrators of the heinous crime, he added.

       Located a few kilometers from the border with Burkina Faso, Bawku has recently been enmeshed in armed unrest due to a protracted chieftaincy dispute and other criminal activities.