Bomb suspect spent weeks in Ghana before flight

* Christmas Day bomb suspect spent weeks in Ghana

* Ghana installing full body scanners at airport

ACCRA, Jan 4 (Reuters) - A Nigerian man charged with trying to blow up a U.S. airliner bound for Detroit on Christmas Day spent weeks in Ghana immediately before starting his journey, a Ghanaian official said on Monday.

Ghana was unaware of any security alert on Umar Farouk Abdulmutallab, 23, when he arrived in the West African country, Deputy Information Minister James Agyenim-Boateng told Reuters.

"He got in and was processed by immigration as any other ECOWAS citizen because we had no knowledge of any security alert on him," Agyenim-Boateng said, referring to a regional bloc.

Abdulmutallab arrived in Ghana on Dec. 9 from Dubai and left on Dec. 24 for Lagos, Nigeria, from where he flew to Amsterdam and then to Detroit.

While in Ghana Abdulmutallab, who gave a Dubai address, did nothing to arouse suspicion, Agyenim-Boateng said.

Ghana has bought full body scanners to be installed at the Kotoka International Airport in Accra as part of measures to tighten security, he said. Explosives were found strapped to Abdulmutallab's leg.

Nigeria and the Netherlands have also said they will introduce full body scanners, Italy will use them on passengers boarding some flights, and Britain's BAA airport operator says it will move quickly to install them at London's Heathrow airport. (Reporting by Kwasi Kpodo; Editing by Daniel Magnowski; Editing by Charles Dick)