Bahrain's top Shia cleric Sheikh Isa Qassim hospitalised

Bahrain's leading Shia cleric Sheikh Isa Qassim, a key opposition figure, has been admitted to hospital in critical condition, his family and a rights group said on Monday.

Sheikh Qassim, in his late 70s, is a spearhead of Bahrain's opposition movement demanding an elected government in the Shia-majority kingdom, ruled for more than two centuries by the Sunni Al-Khalifa dynasty.

Qassim was stripped of his citizenship in 2016 on charges that include "serving foreign interests", an allusion to Shia-ruled Iran. He has been under de facto house arrest ever since.

Nedal al-Salman, acting president of the Bahrain Center for Human Rights, and a relative of Qassim who requested anonymity both confirmed Qassim was in critical condition. 

Authorities allowed his family to transport him to a hospital of their choosing after they declined state-sanctioned medical care. 

The cleric's ailing health has for weeks been a point of contention between authorities and the Qassim family, who had refused the government's offer to transfer him to hospital over fears he may be detained and deported should he leave his residence. 

While his family has not made public the details of his condition, rights groups say he has high blood pressure, diabetes and heart disease. 

The Shia majority in Bahrain, which has been ruled by the al-Khalifa dynasty for more than two centuries, has long complained of marginalisation and the country has been rocked by sporadic unrest since 2011.

Authorities have since tightened their grip on dissent, jailing hundreds of protesters and stripping a string of high-profile activists and clerics of citizenship. 

Last month, Bahrain charged jailed Shia opposition leader Sheikh Ali Salman with "spying" for Qatar, state prosecutors said, after allegations he whipped up protests at Doha's request.

The investigation into purported links between Salman and Qatar was first launched in August, after a quartet of Arab countries, including Bahrain, accused their gas-rich neighbour of supporting terrorism and close relations with Iran – allegations Doha vehemently denies.

State-run Bahrain Television aired a report which claimed that neighbouring Qatar was behind anti-government protests that have shaken the tiny kingdom for the past six years.