ABU DHABI (REUTERS) - Bahrain has deported a US nursery school teacher whom it says wrote articles on social media sites linked to radical groups and for violating the terms of her work permit as the kingdom intensifies its crackdown on dissent.

The Ministry of State for Communications did not identify the woman but said she wrote under a pen name and had broken the law by working as an unaccredited journalist.

The teacher wrote articles for online publications including As-Safir newspaper, which is linked to Lebanon's Iran-backed Shi'ite group Hezbollah, and the outlawed Bahrain Center for Human Rights newsletter, the state news agency said on Saturday.

No one at the Bahrain Center for Human Rights was available for comment.

The ministry had received a complaint about the woman who used Twitter and other social media to write articles "deemed to incite hatred against the government and members of the Royal family, as well as spreading misinformation and encouraging divisions in Bahraini society based on religious sect", it said.

Bahrain, a majority Shi'ite country ruled by the Sunni al Khalifa family, has been buffeted by unrest since the start of the Arab Spring uprisings in 2011, with mostly Shi'ite Bahrainis agitating for democratic reforms and more say in government.

The island, which is home to the US Fifth Fleet and sits between top oil exporter Saudi Arabia and Iran, has expelled several foreigners for involvement in documenting unrest.

In Feb 2012, two American rights activists were deported for trying to report on events marking the first anniversary of demonstrations for democratic reforms.