SRI LANKA'S government has got its retaliation in first. On April 12th a panel of experts delivered a report to the UN secretary-general, Ban Ki-moon, assessing whether war crimes were committed when the nation's army bloodily won a long-running civil war against Tamil Tiger rebels early in 2009. The report has not yet been made public, but the government is furious that an independent inquiry took place at all. The report, it says, is “fundamentally flawed” and biased.

In recent weeks Sri Lanka's rulers have vented their anger, most obviously by cracking down at home, intimidating those they blame for spurring the launch of the UN inquiry in the first place. At the sharp end are Western-funded education and advocacy groups, notably those keen on post-war reconciliation or those that point out flaws in the government of President Mahinda Rajapaksa. Facing the most intense scrutiny are groups which have complained about repression, a muzzled press and a lack of civil liberties.

Top of the list is the National Peace Council, which pushed for a negotiated rather than a violent end to the war. Last month criminal investigators summoned its director, Jehan Perera, demanding details of the group's funding and operations. Before that, a smear campaign in the press suggested the council takes orders from foreign donors. No specific crime has been alleged, making it harder for the council to clear its name.

Under surveillance, too, is the local branch of Transparency International, an anti-corruption watchdog. In October, after it launched a project to monitor abuse of public resources, investigators called in its accountant to quiz him over “suspicious transactions”. The inquiry was dropped, but the pro-government press has continued to vilify the group.

Most exposed of all are bodies which, as the war reached its climax, spoke up for civilians caught in the crossfire. Fierce army onslaughts finished off the brutal Tamil Tigers, but thousands of civilians were killed, injured or displaced in the process. Human-rights groups in the West backed the activists' campaign. The government strongly denies any abuses and instead attacks the campaigners, saying they have involved foreigners in an internal affair. Now it accuses the NGOs of raking in funds without explaining how they are used, though the groups have offered to show their audited accounts.

Several factors help explain the timing of all this. Some in Mr Rajapaksa's hawkish government seem convinced that his opponents are conspiring with the West or, worse, with the active and educated Tamil diaspora, to discredit him. By spreading the idea that “fifth columnists” fed harmful information to foreign experts, the government hopes to discredit the UN report.

If, in turn, other NGO types are worried by a crackdown, they might become less willing to snipe about other problems in Sri Lanka, such as pervasive nepotism. Journalists, too, might usefully be scared. On March 31st police arrested the editor of a popular pro-opposition website. In Orwellian style, he was accused by the state-run media of being behind a January arson attack that destroyed his own office and equipment. Supposedly, this was to bring the government into disrepute, by getting officials blamed. But scariest of all, one of the website's reporters, Prageeth Eknaligoda, has now been missing for more than a year. It can be dangerous to speak out in Sri Lanka.