Thirty-two tourists disappeared

The reports come a day after Algerian security sources reported that the group had already been freed - only for the reports to be officially denied several hours later.

Algeria's al-Watan newspaper was quoted on Tuesday by Reuters news agency as saying that an assault on the stronghold of militants accused of holding the hostages was only hours away.

However the newspaper said fierce sandstorms and low cloud may have forced a delay.

The paper also said that Algerian army chief of staff, Lieutenant-General Mohammed Lamari, visited his troops in the province of Illizi, 750 miles (1,200 km) south of the capital Algiers at the weekend.

This is near where the hostages are thought to be being held.

Rumours

Another group of 17 tourists was rescued on 13 May after being freed by army commandos.

The first group of hostages have now arrived safely home

Rumours about a possible second rescue attempt have been circulating since then.

The adventure tourists were travelling in the Sahara desert without guides, using four-wheel drive vehicles and motorbikes, when they disappeared between mid-February and mid-March.

The Algerian army says they were kidnapped by the Salafist Group for Preaching and Combat (GSPC) - a group the US has linked to Osama Bin Laden's al-Qaeda network.

'Almost friends'

The German and Swiss foreign ministries have not commented on developments.

"For us it's the same as it was hours, days ago," a Dutch foreign ministry spokesman told Reuters in reaction to the latest reported rescue and subsequent denial.

"We don't know anything about any action or any release of prisoners."

The first group of freed hostages - 10 Austrians, six Germans and a Swede - arrived home last Wednesday after being rescued by commandos.

At a news conference on Monday, some of the Austrians spoke about their time in captivity.

"We almost became friends," former hostage Ingo Bleckmann said.

He stressed the militants did not put the hostages' lives in danger during the gun battle which led to their release.