Cilvegozu, Turkey (CNN) -- A Syrian opposition group says it was the target of a deadly blast at a Turkish border gate near Syria on Monday that left at least 14 people dead and 28 wounded.
"When the explosion happened, we were supposed to be there. But we were delayed for maybe half an hour," said George Sabra, a leader of the opposition Syrian National Council.
Sabra said he was part of a 13-member group from the council's executive bureau that was traveling from Turkey to Syria on Monday to meet with commanders of the rebel Free Syrian Army.
Their journey through the Turkish border gate at Cilvegozu was delayed by a prayer.
"We stopped at a gas station, and some of our group went to a small mosque to pray there for half an hour," Sabra said. "My mother always said to me, 'God bless you.' Maybe this time He responded to her."
Dozens of other Syrians and Turks at the border crossing were not so fortunate.
On Monday afternoon, Turkish officials said, a minivan drove from the Syrian rebel-controlled side of the border compound and parked next to the first Turkish checkpoint.
Later, that vehicle blew up.
"A minute after the initial explosion, another explosion occurred. This may have been the gas tank of a nearby car," Turkish Interior Minister Muammer Guler told reporters Monday night.
"It was a strong explosion. Our colleagues are working on identifying the explosive," he added.
The death toll was initially placed at 13. Later, Turkish officials and the opposition group said it had risen to 14.
This was not the first time the violence in Syria has spilled across the border to claim Turkish lives. But the border blast was clearly the deadliest incident in Turkey since the Syrian uprising began 23 months ago.
In October, five Turkish civilians were killed when Syrian troops shelled the Turkish border town of Akcakale. And in June, Syrian anti-aircraft fire brought down a Turkish military reconnaissance jet over the Mediterranean Sea.
When fighting erupts across the border, Turkish authorities periodically close schools that are close to Turkish territory.
The Turkish government has been reluctant to call Monday's explosion an act of terrorism.
Recep Tayyip Erdogan, Turkey's often fiery prime minister, made a restrained, somewhat ambiguous statement to the Turkish media Monday.
"This event illustrates how on target we have been in terms of our sensitivity to both terrorism and to the events in Syria. We will not make concessions on either front," Erdogan said.
Turkey has hosted more than 170,000 Syrian refugees since Syria's uprising and subsequent government crackdown began in March 2011.
As violence intensified inside Syria, the Turkish government turned its back on Syrian president Bashar al-Assad and threw its support behind the Syrian opposition.
Turkey has provided medical care and financial and logistical support to Syrian rebels. The Turks have also permitted shipments of weapons and ammunition to cross the border to rebels inside Syria.
If, as the evidence suggests, Monday's attack was a car bomb, the list of potential suspects is quite long.
Earlier this month, a violent Turkish leftist group claimed responsibility for a suicide attack on the U.S. Embassy in Ankara, killing a Turkish guard and seriously wounding a Turkish journalist.
For nearly three decades, Kurdish separatists have fought a guerrilla war against the Turkish state.
And al Qaeda and other radical Islamic groups have carried out deadly attacks in Turkey.
The opposition Syrian National Council has accused the Syrian government of planning Monday's explosion, but has not offered any evidence to back up that claim.
On Tuesday, Turkish gendarme units established a checkpoint blocking civilian access to the Cilvegozu border terminal.
And in the nearby town of Reyhanli, families were burying victims of the mysterious blast.
Hundreds of mourners watched as the wife and young son of 34-year-old Ahmet Tas, a Turkish citizen killed in the attack, screamed in despair.
His coffin was buried in a cemetery not far from the Syrian border.