Bahrain has accused wealthier neighbour Qatar of harming its national security by “luring” some nationals to take Qatari citizenship, state news agency BNA said, a charge that could widen a rift among Gulf Arab countries.

Bahrain, Saudi Arabia and the UAE recalled their ambassadors from Doha in March, accusing Qatar of failing to honour an accord not to interfere in each others’ internal affairs.

The countries are all members of the Gulf Cooperation Council (GCC), along with Kuwait and Oman.

Efforts to patch up the rift, centred around Qatar’s backing for the Muslim Brotherhood movement which the other countries oppose, have so far failed.

BNA quoted the interior ministry’s undersecretary for nationality, passports and residence affairs, Sheikh Rashid bin Khalifa Al-Khalifa, as saying Qatar had “targeted specific families and singled out a particular category of people” with no consideration to Bahraini laws. “The naturalisation of Bahrainis would affect Bahrain’s national security and vital interests negatively,” the agency said on its English website, quoting the official. Sheikh Rashid gave no details on who was being targeted for naturalisation.

Bahrain is acutely sensitive to changes in its demographic balance between Shias and Sunnis. The Sunni-ruled kingdom has a Shia majority and an ongoing conflict between authorities and predominantly Shia protesters calling for more democracy has strong sectarian elements.