Sudan has broken up a group of Sudanese plotting to attack the French, British, U.S. and U.N. diplomatic missions in Khartoum, caught most of them and seized arms and explosives, the state news agency SUNA has said.

SUNA quoted foreign ministry spokesman Ali al-Sadig as saying late on Sunday that the authorities had caught all but two of the group and were continuing the search for those two.

A senior ministry official met French, British, U.S. and U.N. diplomats in Khartoum to tell them of specific threats against them by Sudanese arrested last week with grenades, explosives and other weapons, SUNA said.

The official briefed the diplomats on "events related to some groups recently arrested with explosives who were targeting these specific embassies," SUNA quoted Sadig as saying.

"The government is completely committed to offer the (embassies) all the protection possible to allow them to work in safety and security," Sadig told SUNA.

Interior ministry sources said last week that the Sudanese police had arrested eight Sudanese in connection with the discovery of three weapons caches in the capital, containing mainly grenades and ammunition.

Britain's Foreign Office warned Britons on Saturday not to travel to Khartoum because of heightened fears that Western interests might be attacked.

The British embassy told Britons living in Sudan on Saturday to be vigilant and review their security arrangements. It closed its public services on Sunday and Monday and cancelled its regular Thursday night social club.

An interior ministry source said last week that many former rebel armed groups had entered the Sudanese capital since the signing of the north-south Sudan peace deal and the recent Darfur agreement, and arms had become more common.