(CNN) -- Libya said Saturday it will seek extradition of its former spy chief who was arrested in Mauritania and is wanted for war crimes by the International Criminal Court.
Mauritanian security authorities arrested Abdullah al-Senussi, Libya's former chief of intelligence and one of the Gadhafi regime's most wanted men.
Al-Senussi, the late Moammar Gadhafi's brother-in-law, was arrested Friday evening at Nouakchott airport, a Libyan transitional government spokesman said.
He was carrying a fake passport from Mali at the time of his arrest.
France is also in the process of requesting al-Senussi's extradition from Mauritania, President Nicolas Sarkozy's office said.
Al-Senussi is the subject of an international arrest warrant following his sentencing in absentia to life imprisonment for the September 19, 1989, terror attack on UTA flight 772, killing 170 people, including 54 French nationals, when the French airliner exploded over Niger.
His arrest Friday was the result of joint efforts by the French and Mauritanian authorities, Sarkozy's office said. The Libyan authorities were kept informed, the statement added.
House Minority Leader Nancy Pelosi said that if "Senussi is indeed apprehended, of course that would be good news all around."
"We have a particular interest because of his role in the Lockerbie bombing situation, but it's really good news for the people of Libya."
In 1988, Pan Am Flight 103 exploded over Lockerbie, Scotland, killing all 259 passengers and crew aboard in an attack that was later linked to Libya.
Pelosi, who is leading a congressional delegation that traveled to Libya on Saturday, said al-Senussi's detainment could bring some form of "closure," which she described as "very important."
Interpol had issued a Red Notice for al-Senussi's arrest for alleged crimes against humanity. He is wanted by the International Criminal Court in the Netherlands to stand trial on those charges.
Al-Senussi was detained at the airport along with a younger man believed to be his son, said Libyan interim government spokesman Nasser al-Manee.
CNN's Jomana Karadsheh and Alex Felton contributed to this report.