Israel's militia allies in southern Lebanon, the South Lebanon Army, say they have freed 27 detainees from prison in what correspondents say could be a deal linked to news of a missing Israeli airman.

Three women and 22 men, who had been held without trial at the Khiam prison in the Israeli-occupied zone of south Lebanon, were handed over to officials from the International Committee of the Red Cross.

Two other Lebanese, reported to be Hezbollah guerrillas by Reuters news agency, were released from Shikma Prison in Ashkalon, Israel.

An SLA statement said the releases were timed to coincide with the end of the Muslim holy month of Ramadan, but gave no further details. The releases had been expected last week but were delayed.

Lebanese security services said the released prisoners were all elderly or ill.

It is estimated that at least 120 Lebanese are still being held without trial in Khiam jail.

They were held for allegedly helping Lebanese-based groups who are fighting to force Israel from the occupied area, which Israel calls a security zone.

Human rights organisations, such as Amnesty International, describe Khiam as a brutal jail where torture takes place. The jail is manned by the SLA under Israeli supervision.

Missing airman

The latest release of prisoners comes after five Hezbollah guerrillas were released last month.

The head of Hezbollah, Sheikh Hassan Nasrallah, said in an interview shown by Qatar's al-Jazeera television on Thursday that those releases were made in return for a promise by the resistance group to help determine the fate of Ron Arad, an Israeli airman who was shot down over Lebanon in 1986.

Sheikh Nasrallah said he hoped Mr Arad would be found alive and exchanged for Lebanese prisoners.

Hezbollah has repeatedly denied holding Mr Arad captive but add that it is in their interests to find him if he is alive.

The Khiam releases on Thursday came as Lebanese state radio reported that Israeli warplanes were firing on southern Lebanon.

Last December, Israel released, for the first time since the start of the peace process, Palestinians who had killed Israelis or tourists.