And Mohammed Cheikh Omar, a brother of Ammar Cheikh Omar, one of the captured members of the NBC team, told CNN that his brother said the kidnappers were a group claiming to be Free Syrian Army.

Ammar Cheikh Omar said the group that freed the crew was a Free Syrian Army brigade called Ahrour el Sham.

The Observatory named the rebel group that freed the crew as the Freeman of the Levant Brigades.

In other developments:

Other hostages still held in Syria

A Ukrainian journalist, Ankhar Kochneva, continues to be held by Syrian rebels who have reportedly threatened to kill her unless a hefty ransom is paid.

The rebels have given the Ukrainian government more time to meet their demands, the official RIA Novosti news agency reported Tuesday.

And Russian Foreign Minister Sergei Lavrov said Tuesday that Moscow was taking "all the necessary steps" to free two Russian citizens abducted in Syria on Monday, RIA Novosti reported.

Their captors have demanded a ransom payment, the state-run Itar-Tass news agency cited the Foreign Ministry as saying.

The two Russians, who work for a private company in Syria, were seized near the port city of Latakia, Itar-Tass reported. An Italian engineer was kidnapped alongside them.

Blasts shake Palestinian refugee camp in Damascus

Explosions rang out inside a densely populated Palestinian refugee camp in Damascus as clashes erupted again between rebel fighters and a pro-government Palestinian militia, the Syrian Observatory for Human Rights said.

The renewed fighting comes amid wide concern about the humanitarian situation in the Yarmouk refugee camp, home to nearly 150,000 people.

Syrian warplanes bombarded the camp Sunday, hitting a school and a mosque and causing at least 15 deaths, the opposition Local Coordination Committees of Syria said.

Since then, fighting between rebels and a Palestinian faction reportedly led by Ahmad Jibril, a longtime leader of the Popular Front for the Liberation of Palestine General Command, has rocked the camp.

One displaced Yarmouk resident told the pro-Assad Al-Watan newspaper that a large number of Syrian armed forces were gathering to the west of the camp Tuesday.

He said he believes this "may be a lead-up to a military operation to cleanse the camp of the militants."

Mohammad Shtayyeh, a member of the central committee of the Palestine Liberation Organization and head of the relief committee for the Palestinians in Syria, condemned the loss of life in Yarmouk.

He said it was the responsibility of the Syrian government to ensure the safety of Palestinians in their country.

"Palestinian blood should not be part of the struggle for Syria, and the Palestinians are not part of it," he told CNN.