Car Bomb in Jordan, Near Syria Border, Kills 6

AMMAN, Jordan — Four Jordanian soldiers, a police officer and a civil defense officer were killed on Tuesday after a car bomb exploded on the Jordanian border with Syria, according to a statement by the Jordanian Armed Forces.

The attack took place around 5:30 a.m. on the sand berm across from a camp for Syrian refugees in Rukban with more than 55,000 people living in harsh conditions.

No group claimed responsibility for the attack.

Five people, including three officers of the Jordanian intelligence service, were killed in an assault this month at a Palestinian refugee camp near the capital, Amman.

Terrorist attacks in Jordan, a crucial ally of the United States in the region, are relatively rare, but the country is constantly aware of the threat posed by Islamic extremists, notably from the Islamic State, also known as ISIS or ISIL.

The armed forces described the attack on Tuesday, which also left 14 wounded, as a “cowardly murderous act” and vowed that the military would continue to fight terrorism and terrorists and “their dark minds.”

For more than a year, Syrians have been fleeing the civil war to an area over the berm, which was once known for little more than desert sand, scorpions and snakes but is now a populated area vulnerable to traders, smugglers and drug dealers.

The area is home to a demilitarized zone that prevents people from crossing into Jordan but gives relief agencies a place to provide assistance to refugees. A sprawling informal camp on the Syrian side of the border has grown to house tens of thousands of people who fled areas including Aleppo, Homs and Palmyra.

Jordan has cited security and economic concerns tied to the refugees, some of whom come from areas controlled by the Islamic State, in refusing to allow them to cross the border.

Jordan has taken in more than 650,000 Syrian refugees, according to the United Nations refugee agency. A majority of them live outside refugee camps.

Jordan is allowing 200 to 300 refugees from the border area into the country each day, but only after they are subjected to a thorough security screening and after immense pressure from other countries.

Despite the alarming numbers at the berm, aid agencies and the government have been wary of speaking publicly about the refugee situation on the border because they do not want to anger the Jordanian government.

“There still needs to be more clarity as to what happened,” Helene Daubelcour, the senior external relations officer for the United Nations High Commissioner for Refugees. “One thing I can tell you is that our staff is safe and was not affected, but it’s too early to say what will happen now and what the concerns are. It’s just too early to say.”

This month, three officers of the Jordanian intelligence service and two other employees of the service were killed at an intelligence office near Amman, in what the government said was a terrorist attack.

Officials in Jordan said at the time that they had arrested the assailant, but most of the details about the attack remain unknown because of a gag order issued by the authorities.

The intelligence office was part of the country’s General Intelligence Directorate, making it a particularly significant target for militants.

In November, at least five people, including two American trainers, were killed at an Amman training compound by a Jordanian police officer who fired on them before he was shot and killed, the government said.