Key Iraq-Syria crossing 'falls to IS'

 slamic State militants have seized the last Syrian government-controlled border crossing between Syria and Iraq, a Syria monitoring group says.

Government forces withdrew from al-Tanf - known as al-Waleed in Iraq - crossing as IS advanced, the Syrian Observatory for Human Rights (SOHR) said.
The loss of al-Tanf to IS follows the group's takeover of the ancient Syrian city of Palmyra on Thursday.
The US says that fighting the militants will be a "difficult challenge"
 slamic State now controls "more than 95,000 sq km (36,679 sq miles)" of Syria, which is 50% of the country's entire territory, the UK-based SOHR said.
The militants dominate the provinces of Deir al-Zour and Raqqa and have a strong presence in Hasakeh, Aleppo, Homs and Hama.
However, correspondents say there are large areas under IS control in the east that are not very significant strategically.
IS has also been made significant gains in neighbouring Iraq, capturing the strategically-important city of Ramadi in Anbar province after weeks of fighting.
 The ancient site of Palmyra lies on a strategic route through the desert

The BBC's Jim Muir says that the militants, demonstrating the extraordinary momentum they have shown in the past, have not been content to sit and savour the major gains they have made in recent days.
The seizure of al-Tanf, in Syria's Homs province, enables IS to link up its positions in east-central Syria more directly with the ground they hold in Iraq's western Anbar province, he notes.
Militants in Iraq are reported to be pressing eastwards from Ramadi down the Euphrates Valley towards Habbaniya where pro-government forces are massing for a proposed counter-attack on Ramadi.
If they take Habbaniya, IS will be close to linking up directly with Falluja, a city close to Baghdad which has been held by the Sunni militant group for well over a year despite repeated attacks by government forces, our correspondent says.
Iraq's Deputy Prime Minister Saleh al-Mutlaq warned that fighting IS was no longer a "local matter", and called on the international community to act.
"All the world will face this danger if there is not a clear strategy to fight Islamic State," he said.