Spying is as familiar in Beirut as it was in post-war Vienna - there's even a giant "Third Man"-type ferris wheel here - but the events of the last few days are growing more mysterious by the hour. Over the past two weeks, a special unit of Lebanon's Internal Security Force (ISF) has been arresting a clutch of Lebanese allegedly working as spies for Israel.

There are least 21 men and one woman under interrogation and the ISF has been regaling us all with the highly sophisticated Israeli communications equipment found hidden at their homes.

Those detained include a local journalist in the Bekaa Valley and a senior officer in the Lebanese army, a man who was wounded by Islamist gunmen at the battle of Nahr el-Bared in 2007. They've even picked up a retired general and his wife. Colonel Maurice Diab is a much respected soldier, although military officers say that questions were first raised some time ago when he was sent for training to the United States on a government grant but in a photograph taken on the course could be seen standing next to uniformed Israeli officers. He lives in the north Beirut coastal suburb of Antelias, although other arrests are spread across eastern Lebanon and the border village of Rmeish.