Nervous Gulf states appear to be co-ordinating a crackdown on critics in the media and academic world as well as on political activists who challenge the status quo and protest about human rights abuses.

Two leading Bahraini journalists were blocked from entering the United Arab Emirates on Monday for unspecified reasons, just days after the UAE refused entry to Kristian Ulrichsen, of the London School of Economics, who was scheduled to speak about Bahrain at a conference on the Arab spring, which has unsettled all the region’s conservative monarchies.

Mansour al-Jamri, editor of the Bahraini newspaper al-Wasat, was refused entry at Dubai international airport along with his wife, Reem Khalifa, an Associated Press correspondent. Jamri had been due to attend a conference on newspapers but believes the ban stems from a security deal agreed by the six Gulf Co-operation Council (GCC) members last year. “The ban clearly has nothing to do with the conference,” he told the Guardian . “But we were told it was a decision from the top.”

The contents of the pact remain secret but it includes a shared database. GCC security concerns focus on the Muslim Brotherhood, other Islamist groups and Iranian influence, while the ongoing unrest and political tensions in Bahrain have a sectarian character. Restrictions on social media have become common.

The UAE foreign ministry said that Ulrichsen was not allowed into the country because his work had criticised Bahrain’s monarchy, which has faced street protests since the Pearl revolution erupted two years ago. A UAE contingent was part a Saudi-led GCC intervention force deployed in Bahrain in 2011.

“The UAE took the view that at this extremely sensitive juncture in Bahrain’s national dialogue it would be unhelpful to allow non-constructive views on the situation in Bahrain to be expressed from within another GCC state,” the statement said. Ulrichsen had “consistently propagated views de-legitimising the Bahraini monarchy”, it added.

The Manama government, under pressure from western allies, wants a dialogue on reform with the opposition but blames it for violence.

The LSE cancelled the conference on the Arab spring it had planned to hold over the weekend at the American University of Sharjah, in the UAE, citing “restrictions imposed on the intellectual content of the event that threatened academic freedom”. The last-minute cancellation came after the Emirati authorities requested that a presentation on Bahrain be dropped.

Bahrain now routinely restricts access for reporters. A Guardian request for a visa to visit in February was at first rejected on the grounds of inappropriate timing. A request for clarification went unanswered. Then a visa was suddenly issued just before the anniversary of the 2011 uprising, valid for just four days but for immediate use.

“These regimes are particularly nervous about respected voices being heard,” said Rori Donaghy of the Emirates Centre for Human Rights in London. “They are trying to manage dissent with their own populations. They are concerned about people who they can’t dismiss as traitors or members of the Muslim Brotherhood or proxies of Iran. That’s the crux of it.”

Ulrichsen commented in an account of his experience in Dubai: “The monarchies are reacting to the transformative online power of new media and social networking sites by attempting to close down these spaces for free discussion and debate and reminding would-be detractors of the coercive power at their disposal.

“Denying me entry may have been a sovereign right, but it signifies that the gloves are off, and that the UAE currently is a deeply inimical place for the values that universities are supposed to uphold.”

The UAE has cracked down on political dissent since the Arab spring. Ninety-four people charged with conspiring to overthrow the regime go on trial next week amid criticism from rights groups about the lack of public due process in the case.