WASHINGTON, June 20: The US State Department said on Monday that it was unable to “verify facts” about an alleged assassination attempt on the outgoing US ambassador in Afghanistan as reported by Afghan authorities. Afghan officials said earlier on Monday that they have arrested three Pakistani men for plotting to assassinate Ambassador Zalmay Khalilzad during an official visit to eastern Laghman province on Sunday. The arrests came just hours after the US military announced that increasing numbers of foreign militants have entered Afghanistan, apparently to help Taliban insurgents fight the central government.

The Pakistani men were reportedly armed with rocket-propelled grenades and rifles when they were arrested. The US Embassy in Kabul said earlier it could not immediately comment on the arrests.

In Washington, State Department’s deputy spokesman Adam Ereli told a briefing that Afghan police told US authorities they had foiled an assassination attempt against Ambassador Khalilzad and had detained a number of individuals who were plotting to assassinate him.

“We cannot verify the facts as reported by the Afghans,” said Mr Ereli, although the US government had “a very close and cooperative relationship” with Afghan security forces.

“We appreciate and value their efforts and all that they do to protect American diplomats and others working in Afghanistan. We are in contact with them to find out and do what we can to get to the bottom of this,” he added.

Mr Ereli said that despite the threat, Ambassador Khalilzad visited the place “where he was reported to be the target of a plot” as part of his farewell activities on leaving Afghanistan.

He said the ambassador visited a provincial reconstruction team in Laghman and also participated in an event at a disarmament programme.