Syrian refugees who are living at a camp in Jordan face water scarce after Amman closed the border with Syria following a deadly explosion at military post.

Video footage from the Rukban camp shows refugees chanting, "We want water," while multiple residents of the camp said that they have started to drink polluted water, the Associated Press reported on Wednesday.

"Things are getting worse, not better," said a mother of three who fled the Daesh-held city of Raqqah. "We lack water, bread. We need everything," she added.

"Water is the most important thing," said another refugee. "Food is secondary, we can't live without water," he added.

Meanwhile, Amnesty International called on Jordan to reopen the border to refugees fleeing conflict in Syria.

The rights group stressed that Jordan “must not descend into closing the border and denying humanitarian aid to tens of thousands of Syrian refugees fleeing armed conflict."  

"A total closure of the border and denial of humanitarian aid to the area would inevitably lead to extreme hardship among those unable to find refuge and put their lives at risk," it added.

On Tuesday, a bombing attack killed six soldiers and injured a dozen more outside the Rukban camp, which is home to some 60,000 refugees, located in the area where the borders of Iraq, Syria, and Jordan meet.

"Jordan has a duty to protect civilians from armed attacks, but its security measures must not violate its international legal obligations to provide protection and assistance to refugees who are desperately fleeing the very same type of violence," said Amnesty's Sherif Elsayed Ali.

"Denying them entry into Jordan amounts to a violation of international law," he added.

Following the attack, Jordanian Army General Mashal al-Zaben announced that the northern and northeastern border strip with Syria was a closed military zone as of Tuesday.

"Any vehicle and personnel movement within these areas that move without prior coordination will be treated as enemy targets and dealt with firmly and without leniency," he said in a statement.

Syria has been gripped by foreign-sponsored militancy since March 2011. Damascus says Saudi Arabia, Turkey, and Qatar are the main supporters of the militants fighting the government forces.

UN Special Envoy for Syria Staffan de Mistura estimates that over 400,000 people have been killed in the Syrian conflict since March 2011. The UN has stopped its official casualty count in the Middle Eastern state, citing its inability to verify the figures it receives from various sources.