Image caption There have been protests across Pakistan over the US raid to kill Osama Bin Laden

The US military has announced the withdrawal of a number of its troops from Pakistan.

The Pentagon said it had received a request from the Pakistani government to reduce its presence in the country.

The request came after a raid by US special forces killed al-Qaeda leader Osama Bin Laden in early May.

The US has more than 200 troops in Pakistan helping to train the army. But there are said to be intelligence and special forces operating there.

A spokesman at the Pentagon said that within the last two weeks Pakistan had asked the American military to reduce its footprint, and the Americans were doing so, pulling out some troops. The numbers are quite small.

It is not clear if any of the American intelligence and special operations forces that are said to be in Pakistan clandestinely are also being pulled out.

Volatile relations

The request would appear to be a sign of Pakistan's discontent at the manner in which the raid on Osama Bin Laden's compound in Abbottabad was conducted without Islamabad's knowledge.

Relations between Washington and Islamabad are always complex and fragile but they are particularly volatile at the moment.

In Washington, suspicion is rife that some in Pakistan knew of Osama Bin Laden's hiding place.

And there is grumbling about continued US military aid.

A trial underway in Chicago may shed light on the relationship between Pakistani intelligence and violent extremist groups.

And to top it off, Pakistan's Prime Minister Yousuf Raza Gilani has just been to China, buying fighter jets and reaffirming a strategic alliance the US finds troubling.