Britain says it has expelled five diplomats from the Libyan embassy in London because they could pose a "threat" to British security.
It was not immediately clear if the diplomats expelled on Wednesday are supporters of Libyan leader Moammar Gadhafi, who is fighting a rebel uprising against his 42-year rule.
Britain has been part of a Western-led coalition carrying out airstrikes to enforce a U.N. Security Council resolution calling for protection of Libya's civilians and authorizing all necessary measures to stop attacks by Gadhafi's forces.
British Prime Minister David Cameron told lawmakers Wednesday that his government has not yet decided whether to provide arms to Libyan rebels who launched the uprising last month. He said the U.N. resolution does "not necessarily rule out the provision of assistance to civilians in certain circumstances."
Russian Foreign Minister Sergei Lavrov warned Wednesday against arming the Libyan rebels. He said Moscow agrees with a statement made by NATO Secretary-General Anders Fogh Rasmussen that the alliance is conducting operations in Libya to protect the population, not to arm it.
Russia abstained from voting on the U.N. Security Council resolution on March 17 and has criticized international airstrikes on Libya for going beyond the U.N. mandate.
Lavrov said Libya should have a new, democratic government, but that Libyans must decide on it themselves, without influence from the outside.
U.S. President Barack Obama said Tuesday Mr. Gadhafi's camp knows that his reign is reaching an end. In a television interview, Mr. Obama said the "noose has tightened" around Mr. Gadhafi, prompting the Libyan leader's associates to recognize that "their days are numbered," as the U.S. president put it.
U.S. Secretary of State Hillary Clinton said Tuesday U.N. resolutions do not prohibit nations from legally arming the rebels, although no decision has been made to do so.
She was speaking at a London conference where more than 40 countries and international organizations agreed that Mr. Gadhafi must step down.
Representatives at the London conference said they will help opposition leaders form an interim government and set up a contact group to map out Libya's future.