Hamas has largely deserted its headquarters in the Syrian capital in recent weeks, in what has become an unofficial departure by the Palestinian movement.

The exodus reflects both the widely-held belief that the Assad regime is entering its dying days, and the proximity of Hamas to Islamist elements in the Syrian opposition.

Hamas was founded 24 years ago in the Gaza Strip by Palestinian members of the Egyptian Muslim Brotherhood but, for most of its existence, its political headquarters have been in Damascus. Syria, and its main ally, Iran, have been the movement's main backers and arms suppliers.

Officially, Hamas's political bureau is still in Syria, but according to various reports, it has been almost empty over the past couple of months, with senior leaders making only periodic visits.

It is still unclear where the main offices will relocate to and the departing members have so far travelled to a number of Arab countries including Lebanon, Qatar, Sudan and the Gaza Strip. Rumours of an organised move to Jordan or Egypt have so far proved unfounded.

The exit from Syria is not only due to Hamas's unease at being identified with President Bashar al-Assad, whose forces have massacred over 4,000 civilians in the last ten months, many of them in areas aligned with the Syrian branch of the Muslim Brotherhood.

It is also a result of the new position of the Brotherhood in Egypt following this year's revolution, which has boosted Hamas's standing in Cairo. The new closeness between Hamas and the temporary Egyptian administration was a major factor in the Gilad Shalit prisoner deal.

President Assad's sole remaining regional ally, Iran, opposed Hamas's move and, according to Israeli intelligence sources, has drastically reduced its funding of Hamas's military wing in Gaza, transferring the bulk of its support to the more radical Islamic Jihad.