The security forces faced the worst immigrant situation since the Safi riots last year when a mass break-out from the same detention centre at one time threatened to overwhelm the police and army, who were out in full force.

Close to 400 illegal immigrants escaped from the detention centre in the morning and several of them got as far as the roundabout leading to Garibaldi Road in Marsa before the scores of escapees were finally herded back into the centre more than two hours later.

Several policemen, soldiers and immigrants were slightly injured but the security personnel showed great restraint in controlling an extremely tense situation.

The immigrants made their way out by forcing the gates open and their intention was to march to Auberge de Castille, in Valletta, Police Commissioner John Rizzo and AFM Commander Brigadier Carmel Vassallo said.

The immigrants were protesting about being kept in detention and arguing that their detention period was too long, Mr Rizzo said. They escaped in two batches. First a group of around 300 smashed their way through the compound's fence and a second group of about 80 escaped shortly afterwards.

Most of those in the second group were rounded up as they reached the tunnels underlying the airport. However, the first, larger group proved to be more troublesome to control.

As soon as the police heard about the escape at about 9.10 a.m. they mobilised several units.

The first to arrive at the scene were two traffic policemen who tried to block the Kirkop tunnels when they realised the immigrants were about to come through. But they were assaulted by the immigrants who overturned one of the bikes and took the radio from the other policeman. He later found it broken.

A number of immigrants managed to reach the roundabout leading to Garibaldi Road, which by then had been blocked by the police. Helped by soldiers, the police started to shepherd the immigrants back in the direction of the airport and towards the detention centre.

Those who resisted were arrested and placed in prison vans which took them straight back to the detention centre.

Most of the escapees were refusing to return and scuffles broke out with the outnumbered soldiers and policemen who did their best to control the situation without using excessive force.

Some immigrants lay on the ground and the officers had a hard time hauling them up one by one while they were physically attacked by other escapees.

As more reinforcements arrived, the mob was slowly pushed towards the roundabout that leads to the airport, where some immigrants hurling stones at the police.

The immigrants were then directed towards the airport where the road had to be blocked to traffic, causing chaos for a while.

The security forces then managed to push them back through the tunnels, where the immigrants climbed onto the roundabout and hurled more rocks.

Under the scorching sun, the police finally managed to force the immigrants back to the detention centre. At this point some of those who were already inside emerged to rejoin the others and flung stones and bottles at the police. The missiles must have been quite large as they were visible from a good 500 metres away.

Superintendent Ray Zammit was hit by a stone in the chest and was taken to hospital in an ambulance. He was released in the afternoon.

Back inside the centre, the immigrants, wielding sticks and metal bars broken off from their beds, challenged the soldiers and police. Some burnt mattresses and skips as security personnel in full riot gear stood by and waited as the Police Commissioner, the Brigadier and the commander of the detention centre Lt Col Brian Gatt tried to persuade them to calm down.

Some of the immigrants then started shaking the fence violently and shouting and it was only at about noon that the situation appeared to be getting back under control.

The police had called up every member of the force they could muster, fearing the worst. Even members of the forensic section and the commissioner's own private secretariat were on the scene as part of the back-up force.

Apart from Superintendent Zammit, seven other policemen and three soldiers were slightly injured. A small number of immigrants were treated for minor injuries.

Police sources said arraignments were unlikely as it was difficult to identify troublemakers at this stage. It was also difficult to establish whether any of the immigrants were on the run as the army was waiting for them to calm down before doing a head count.

Soldiers were yesterday evening trying to repair the broken fence and at one point immigrants tried to attack them, but the situation was soon brought under control.

Asked about the strength of the fence, Brigadier Vassallo said it was quite sturdy but this was meant to be a detention centre not a prison. Immigrants were cutting holes in the fence on a daily basis, using metal rods broken off the beds, he said.

The Republican National Alliance (ANR) strongly deplored what it called the "violent behaviour and attacks against Maltese security forces as well as the extensive damage caused to both government and private property.

"It is hoped that the ringleaders and those that have injured our soldiers and policemen, and damaged property, will be brought to justice and punished unlike what happened in connection with the January 2005 Safi riots," the ANR said, extending its solidarity with the security forces and their families.

A report into the way the army had handled last year's incidents had criticised some members of the army for using excessive force to quell the protesters.

In a short Department of Information statement last night, the Prime Minister on behalf of the government expressed solidarity with the members of the police force and the army who were injured.