ANKARA, Turkey — Four more people have been detained in connection with two car bomb attacks that killed dozens in a Turkish town near the Syrian border, bringing the number of suspects in custody to 13, Turkey's prime minister said Tuesday.
Syria again rejected Turkey's contention it was involved, condemning the attacks and offering to conduct a joint investigation of an attack it has blamed on Turkey.
Police were still searching for six other wanted suspects, Interior Minister Muammer Guler said. Turkish authorities have blamed the attack on a Marxist group with alleged links to the Syrian intelligence agency, but have not named the group.
Turkish Prime Minister Recep Tayyip Erdogan said the death toll on Tuesday stood at 51 people, including five Syrians.
Saturday's powerful bombings were the deadliest in Turkey in years, shattering the border town of Reyhanli, a main hub for Syrian refugees and rebels fighting against Syrian President Bashar Assad's regime.
In Washington, the White House condemned the bombings, vowing that the attack would only strengthen the U.S. resolve to fight instability and violence in the region.
"We stand with Turkey against such horrific violence," White House spokesman Jay Carney said Tuesday.
Once a close ally of Syria, Turkey has turned into one of the Assad regime's harshest critics. I
Syria's Information Minister Omran al-Zoubi said later that Erdogan's government was "taking political advantage of Reyhanli's bombings." He said Syria would be willing to take part in a "joint and transparent investigation by special agencies in both countries."
Erdogan, who previously rejected the Syrian denial of involvement as a lie, dismissed the offer of a joint investigation.
"At the moment, there isn't a legitimate administration accepted by the Syrian people," Erdogan said. "There isn't (an administration) we can conduct any joint work with … How can we accept an administration that is not accepted by the people?"