Prosecutors in Berlin and the neighboring state of Brandenburg are interviewing former members of East Germany's secret police about the 1988 Lockerbie bombing.

All 259 people on board and 11 on the ground were killed when Pan Am Flight 103 ?blew up over the Scottish town of Lockerbie.

Berlin prosecutors said Thursday on Twitter they have received a request for assistance from Scottish authorities "on the basis of which several alleged Stasi employees are questioned, including in Berlin."

German news agency dpa reported that prosecutors in Frankfurt an der Oder, 80 kilometers (50 miles) east of Berlin, received similar requests. The ex-Stasi members are considered possible witnesses, not suspects.

Libyan Abdelbaset al-Megrahi was convicted of the bombing in 2001. He maintained his innocence until death in 2012.