Istanbul (CNN) -- A top Turkish official said Saturday that authorities believe those responsible for a pair of deadly car bombings earlier in the day had been in contact with the Syrian government's secret police force.
In a news conference, Deputy Prime Minister Besir Atalay said the Syrian government was linked to the attack.
"The investigation into the perpetrators is for the most part complete. It has been determined that the organization and its members who carried out the attack were in contact with pro-Syrian regime Al Muhabarat (Syrian Intelligence Services) organization in Syria," he said. "The organization is identified and for the most part the persons involved are identified. "
Atalay added that license plate checks have been "completed" and "the organization and its members (behind the attacks) have been largely identified."
But Syria's information minister denied that his country had any involvement in the bomb attacks. Omran al Zoubi made the comments Sunday while speaking to journalists in Damascus on Syrian TV.
"We were saddened yesterday for the fall of martyrs in Turkey," al Zoubi said. "In one way or another; Turkish people are the Syrian brothers."
The two car bombs exploded Saturday afternoon in the southern Turkey town of Reyhanli, according to Turkish Interior Minister Muammer Guler. In addition to the 43 people dead, 29 people were injured critically, said Guler. Atalay added that 50 people were still hospitalized as of Saturday night.
The first blast occurred at about 1:55 p.m. at the municipality building, which houses city government offices. A second, more powerful blast occurred in front of the post office.
In both cases, cars were loaded with large amounts of explosive material, according to Guler. There was a third explosion of a diesel fuel tank elsewhere in Reyhanli, but Guler said this was ruled an accident.
Abu Marwan was just outside of the town when he heard the blasts and hurried to the scene of one of them, where he saw "body parts everywhere."
"Buildings and the walls of buildings are collapsed," Marwan said. "The windows, the cars, everything is burned around it, people are burned. So many injured. The scene is outrageous, may God grant us peace."
A video posted on YouTube showed a column of thick, black smoke rising from the center of town; another video showed what appeared to be where one of the bombs erupted. Rescuers were pulling bloodied people from the street, the side of a building had been torn off and the windows of the building across the rubble-crusted street had been blown out.
CNN is not able to confirm the videos' authenticity.
The blast drew swift condemnation internationally, including from U.S. Secretary of State John Kerry, who vowed that Washington will "stand with our ally, Turkey."
The report came shortly after the Local Coordination Committees for Syria, an opposition group, reported that Syrian government forces had fired several shells toward Reyhanli, which is in Turkey's southern province of Hatay.
Several Syrians were among the casualties, according to the Syrian Observatory for Human Rights, another opposition group.
But that did not spare Syrians residents of the town from being blamed by residents. "People with sticks in their hands are going after Syrians," Marwan said. "We almost have more Syrians here than Turks, and people are getting angry."
The town's location in Hatay province along the southern border with Syria "carries sensitivity," Prime Minister Recep Tayyip Erdogan told reporters here, according to AA. "Around (20,000) to 25,000 Syrians live here in camps as our guests. Certain steps as in Reyhanli today may be taken to affect the sensitivity in Hatay by those not willing to accept the status quo."
Turkey hosts more than 190,000 Syrian refugees in state-run camps, and more Syrians who have fled their country to Turkish cities and towns. In addition, Turkey has played a major role in providing assistance and a relatively safe springboard for operations to Syrian opposition groups.
The timing of the blasts comes as momentum toward a resolution of the Syrian issue has grown, said Foreign Minister Ahmet Davutoglu, AA reported. "Such blasts taking place on Saturday were no coincidence," he told reporters in Berlin, where he was on an official trip.
"The tranquility and stability of the Turkish Republic and our citizens have priority more than anything else," he said. "It is possible that certain sides may want to sabotage Turkey's tranquility. No power would be successful in hurting Turkey's tranquility."
In a statement, the opposition Syrian National Coalition condemned the attacks.
"The Coalition sees these heinous terrorist acts as an attempt to take revenge on the Turkish people and punish them for their honorable support for the Syrian people, including their welcoming of Syrian refugees who have fled the regime's crimes in their villages and cities," it said. "The Coalition views this attack as a desperate and failed attempt to sow discord between the two peoples."
The conflict in Syria has repeatedly spilled across borders to Turkey, prompting Turkish security forces to reinforce the frontier. At Turkey's request, the NATO military alliance deployed several Patriot missile batteries to protect Turkish border cities from the threat of Syrian missile attacks.
This story was reported by Gul Tuysuz in Istanbul and reported and written by Tom Watkins in Atlanta. CNN's Talia Kayali contributed to this report.