The U.S., in designating al Nusra as a terrorist organization, called the group an alias for al Qaeda in Iraq.
U.S. intelligence agencies believe al Qaeda in Iraq has provided a steady stream of fighters to work with al Nusra.
That might explain why the head of al-Nusra, Abu Mohammed al-Jawlani, claimed in an audio message released on Wednesday that he wasn't "consulted" on the announcement of the merger of the Syrian and Iraqi wings of al Qaeda.
The United States has designated al-Nusra Front as a pro-al Qaeda terrorist group.
The U.S. State Department labeled al-Nusra Front a foreign terror organization linked to al Qaeda in Iraq back in December.
Last month the U.S. government blacklisted al-Nusra, declaring it a terrorist organization linked to al Qaeda.
CNN: Rebels in northern Syria pin hopes on airbase's downfall
Reuters news agency quoted a spokesman for the main Syrian rebel group, the Free Syrian Army, as saying al-Nusra had overrun state security and military intelligence compounds in al-Shaddada.
The U.S. has designated one of the Syrian rebel groups, the al-Nusra Front, as a terrorist organization because of its purported ties to al Qaeda.
But al-Joulani distanced himself from al-Baghdadi's message, saying it took al-Nusra off guard.
The US has put al-Nusra on a blacklist of terrorist organisations.
"We have proof, " he said of al-Nusra's chemical weapons use.
My read of al-Nusra, however, is that, like Zarqawi, it does not aspire to be a political player and is unlikely to settle for a political role in the new government.
The Qatari support does not appear to be going to the most hard-line militant or ultraconservative fighters, such as al-Qaida-linked Jabhat al-Nusra, but rather toward organizations with a conservative religious ideology, away from brigades with a secular or nationalist bent.
The Syrian government says the Nusra Front has ties to al Qaeda.
The U.S. State Department recently listed the Nusra Front, which has close ties to al Qaeda in Iraq and a strong anti-Western ideology, as a terrorist organization.
应用推荐