London (file)
London (file)Thinkstock

London police have arrested four suspected Islamic terrorists in several raids throughout the British capital, The Associated Press (AP) reported on Tuesday.

The report quoted local police who said that officers fired a stun gun at one 21-year-old suspect, but he did not need medical treatment. The four suspects are aged 20 and 21.

Police say they were arrested on suspicion of preparing or instigating acts of terrorism, according to AP.

Armed police from a specialist unit took part in one of the raids, indicating that the situation was deemed potentially dangerous to officers.

Police said no shots were fired when the search warrant was executed.

The suspects remain in custody, and homes and vehicles in west and central London are being searched as part of what police called an ongoing investigation into Islamic-related terrorism.

The terror threat in the UK was recently raised to "severe" because of the increase in the number of Britons traveling to Syria to join up with the “Islamic State” (ISIS) group. The government has said the group plans to strike targets inside Britain.

The issue is also of concern to other countries around the world, including Russia, the U.S., Canada and France, all of which have had local citizens traveling abroad to join ISIS and other jihadist groups.

Statistics published in February said that over 75,000 foreign nationals had been fighting in the Syrian civil war. Several months ago, Britain began revoking the citizenship of its nationals who join the Syrian civil war.

Australia recently apprehended an Islamist terror cell whose members planned to behead a random member of the public.