Thousands of fleeing Syrians stranded at border with Jordan

The kingdom, which is already home to more than 630,000 Syrian refugees - many more if unregistered refugees are added - introduced additional security checks at the Hadalat and Rokbane border crossings at the start of the year, leading tens of thousands more to congregate along the frontier.

"The number of refugees has hit 59,000 at Rokbane and it's rising," the head of Jordan's border guards General Saber Al-Mahayra told reporters on Thursday.

Another officer told AFP that 5,000 others were massed at Hadalat, around 70 km further west.

Mahayra said nearly 5,500 had arrived at Rokbane in the last 24 hours, an influx he attributed to increased fighting around Syria's second city Aleppo, where more than 280 civilians have died in recent weeks.

Jordan has insisted it must screen newcomers to ensure they are genuine refugees and not extremists seeking to infiltrate the country.

The kingdom is now allowing in only a few dozen refugees each day after screening.

According to Mahayra, around 2,000 Syrians currently camping near the border are suspected by Jordanian authorities of involvement with Islamic State.

Weapons have already been seized from some would-be refugees along the border, he added.

After Syria's conflict erupted in 2011, Jordan initially kept open 45 crossing points along its 378 km frontier.

But after a mass influx into the kingdom - Amman says the true number of Syrians in Jordan is closer to 1.4 million - there are now just five crossing points open, and three of those are reserved for the wounded.

Syria's conflict began with anti-government protests but fighting quickly escalated into a multi-faceted war that has killed more than 470,000 people and forced millions from their homes.