The UK has sent a special team of forensic detectives from the Metropolitan Police to Bahrain to help local authorities investigate a recently discovered cache of bomb-making material, the BBC reported on Monday.

Clashes between police, loyal to the Sunni Muslim government, and protestors from Bahrain's Shia majority have been common since the Arab Spring reached the tiny kingdom in February 2011, but the bomb-making materials marked a change in tactics and could not have been put together without help from outside the country, according to a senior government official quoted by the BBC.

Blame has fallen on Lebanese political-military group Hezbollah and the Iranian government, both Shia-majority institutions. Meanwhile, Tehran has blamed Britain of supporting a regime that is brutally repressing its people.