Dubai: The head of Bahrain’s largest Shiite opposition group was to face prosecutors on Thursday after police in the kingdom interrogated him over a meeting with a senior US diplomat.

Cleric Ali Salman, who heads Al Wefaq, and his political assistant, former MP Khalil Marzouq, were summoned by police on Wednesday to appear before the public prosecutor, the movement said.

The action came after police questioned them the same day about the “meeting with US Assistant Secretary of State” Tom Malinowski and the “political situation in Bahrain and the region,” said Al Wefaq.

On Monday, Bahrain told Malinowski, who is the assistant secretary of state for democracy, human rights and labour, that he was “unwelcome” in the kingdom and should “leave immediately.”

Bahrain’s interior ministry confirmed that Salman and Marzouq were questioned separately on Wednesday over the meeting with Malinowski.

Al Wefaq said the move “accentuated the crisis” in Bahrain and demonstrated “the lack of willingness for dialogue” on the part of the authorities to resolve the issue.

The ministry said the meeting at the US embassy violated a rule stipulating that contacts between political associations and foreign parties “should be coordinated with the foreign ministry and in the presence” of its representative.

The rule also stipulates that the justice ministry, which oversees political associations, should be informed of such meetings “at least three days in advance.”

The interior ministry said the two opposition figures were allowed to leave after questioning, and that the public prosecutor would decide on any eventual action.

Al Wefaq said on its Facebook page that Salman’s lawyers were not allowed to attend Wednesday’s questioning focused on the meetings with Malinowski.

The foreign ministry said Malinowski had met “with a particular party to the detriment of other interlocutors,” describing his action as an “interference in its internal affairs.”

The United States State Department has said it is “considering its response” to Bahrain’s expulsion of the US diplomat.

In a press briefing on Tuesday, US State Department spokesperson Jen Psaki said that the US was still considering how to respond to the move.

“We’re considering our response to the government’s decision. But again, obviously, this is new yesterday. So I don’t have anything to outline in that regard,” she said.

On Tuesday, Malinowski wrote on his Twitter feed that Bahrain’s decision was “not about me but about undermining dialogue,” and that “those committed to reconciliation should not be deterred.”

The state department reportedly retweeted the tweet, but asked by a journalist if the retweet was an endorsement, Psaki said: “I wouldn’t put it that way”.

Malinowski was the Washington director for Human Rights Watch, a vocal critic of Manama’s crackdown on protests, until he took his current job in April.

Street protests erupted in Bahrain in February 2011, taking their cue from uprisings elsewhere in the Arab world and demanding democratic reforms in the country.

Security forces boosted by Saudi-led troops quelled the protests a month later, but smaller demonstrations sporadically take place in villages, triggering clashes with police.

The foreign ministry said relations between Manama and Washington would not be affected by the “unfortunate acts” of Malinowski.