Riot police fired warning shots in the air this afternoon as they sought to control a riot by some 70 Nigerians and Somalis at Hal Far detention centre.

The riot was sparked by a visit to the centre by a parliamentary delegation on a fact-finding mission.

In a statement, the Ministry of Home Affairs said the police and detention service officers were attacked with stones, wood and other items from the second floor of one of the blocks at the detention centre.

After a number of warnings, the police fired warning shots which the ministry insisted, were not aimed at the migrants or the windows of the building.

The ministry said that rubber pellets had been fired and not rubber bullets, as reported in the media. The pellets, it said, were not meant to injure. 

The situation calmed down after the warning shots.

The ministry said a migrant who was seen being taken into an ambulance was not hurt but had been taken ill. No one was injured. 

The riot started during a visit by members of the parliamentary Immigration Committee.

The MPs, led by Deborah Schembri, were carrying out a fact-finding visit. The delegation also included Marlene Pullicino, Claudette Buttigieg and Jason Azzopardi.

As soon as they saw them, some of the migrants started shouting and protesting about their detention, with one of them shouting "We are not criminals, we are not slaves."

The MPs could hear the sound of furniture being broken as they were escorted out of the centre.

The MPs were quickly escorted out of the detention centre and police reinforcements were called in.

Policemen in riot gear, some of them armed with rifles, surrounded the large two-storey block and then started to slowly force their way in, ordering the migrants to lie down.

Some migrants were seen carrying what looked like sticks. They shouted insults against Malta and the police.

Two of them were seen resisting the officers as they tried to handcuff them.

Policeman was seen shooting in the general direction of the block's windows. 

A taser gun was also used against a migrant.

The police arrested a number of migrants and one was seen being taken away in an ambulance.

A migrant shouted from a first floor window: "There is no democracy in Malta, no freedom, I have been locked here for six months, every day they tell me tomorrow I will be free."

Calm appeared to be restored at about 2.20 p.m. although the police maintained a heavy presence for some time afterwards.

Seven migrants are expected to be taken to court.