Two Palestinian employees of the UK consulate general in East Jerusalem have been arrested over an alleged weapons plot, Israeli officials say.
The UK Foreign Office confirmed the arrests, allegedly linked to plans to fire a rocket at a football stadium.
The men, who had maintenance jobs and did not have sensitive security clearance, allegedly helped obtain weapons for two others behind the plot.
No rockets were found and the plot was in its preliminary stages, police said.
A Foreign Office spokeswoman told the BBC that the arrests of their employees, which happened several weeks ago but were subject to a gagging order, were unconnected with their work.
However, the BBC's Wyre Davies says the incident will raise concern about vetting procedures at the consulate, which is situated in one of the most politically sensitive parts of Jerusalem.
East Jerusalem is considered occupied territory under international law. Israel took over the predominantly Arab area in 1967, then annexed it in 1981 and sees it as its exclusive domain.
Israel claims the city as its eternal, undivided capital, while Palestinians want East Jerusalem to be the capital of any future Palestinian state.
The international community does not recognise Jerusalem as Israel's capital, and most countries maintain embassies in Tel Aviv.
The Foreign Office spokeswoman said the two consulate employees were suspected of trying to obtain weapons for an alleged attack on Teddy Stadium, the home of the Beitar Jerusalem football team.
Israel's Shin Bet security service has said that two other men were plotting to carry out a rocket or missile attack on the stadium - although it is believed the attempt never got further than the planning stage.
Both of these alleged plotters - named as Musa Hamada from the east Jerusalem district of Sur Bahr and his friend, Bassem Omeri, an Israeli citizen from Beit Safafa - are accused of having been operatives of the Islamist militant group, Hamas, on the Temple Mount/Haram al-Sharif, the most important religious site in Jerusalem.
Their activities included systematically checking how best to launch a rocket while the stadium was crowded with people during a game, officials said. They also allegedly visited a nearby hillside to survey the area.
According to Shin Bet, the two began planning the attack after the Israeli military offensive on the Gaza Strip in December 2009. They also acquired a number of rifles to carry out additional attacks, it added.
Mr Hamada and Mr Omeri, who were arrested in November, were charged on Sunday with being members of a terrorist organisation, illegal use of weapons and planning an attack, Shin Bet said.