Algerian authorities are fighting Islamist militants
Ben Bradshaw, a UK Foreign Office Minister, says Britain does not want to be regarded as a haven for terrorists, but that it cannot act against suspects living in the UK without having firm evidence.
Mr Bradshaw was speaking in Morocco, a day after the Algerian Government repeated to him its call for the UK authorities to expel Algerian Islamist militants implicated in violence against civilians in Algeria and France.
Mr Bradshaw said that even before the 11 September attacks on New York and Washington, the UK Government took firm measures against terrorism by proscribing a number of organisations, including two Islamist groups using violence against civilians in Algeria, the GIA and the GSPC.
Mr Bradshaw said the authorities would take legal action based on the anti-terrorism law whenever there was evidence that would stand up in court.
But he said much damage could be done if suspects were arrested only for their cases to be lost because of insufficient evidence.
Support welcomed
Mr Bradshaw said he welcomed the support from Algeria and Morocco for an international coalition against terrorism in the wake of the American attacks.
He noted how the two countries, which had their political differences in other areas, were united in this respect.
The main regional dispute, the issue of sovereignty in the Western Sahara, has also been a key discussion point during the UK minister's north African tour.
The Moroccans in particular, he said, were positive about new proposals for the region to become autonomous and he welcomed this development.
Mr Bradshaw returns to Britain on Wednesday.