The U.N. Security Council is holding its second emergency meeting in a week about North Korea on Monday after a powerful nuclear test explosion added another layer of urgency for diplomats wrestling with what to do about the North's persistent weapons programs.

Scheduled after North Korea said it detonated a hydrogen bomb underground Sunday, the emergency session comes six days after the council strongly condemned Pyongyang's "outrageous" launch of a ballistic missile over Japan. Less than a month ago, the council imposed its stiffest sanctions so far on the reclusive nation.

Dozens of Islamic State group members and their families have crossed into areas controlled by the extremists despite U.S. threats to bomb the convoy days after they left the Lebanon-Syria border, Syrian opposition activists say.

The opposition activists' announcement came after the U.S.-led coalition fighting IS said the 17-bus convoy of IS militants and their families that left the Lebanon-Syria border six days ago is still stranded in the Syrian desert.

U.N. Secretary-General Antonio Guterres has welcomed the extension of a longtime peacekeeping operation in Lebanon, reiterating support for a commander who drew U.S. criticism.

Spokesman Stephane Dujarric said in a statement that the peacekeeping mission, known as UNIFIL, will keep enhancing its operations and Guterres has confidence in its leadership and staff.

The media arm of Hizbullah said Thursday the group has received the body of an Iranian Revolutionary Guard member recently captured and killed by the Islamic State group in Syria.

The handover of Mohsen Haji's body is part of a controversial deal brokered by Hizbullah to clear IS fighters from an area along the Lebanon-Syria border.

The U.N. Security Council on Wednesday extended the peacekeeping mission in Lebanon for another year amid pressure from the United States for the U.N. force to take action against Hizbullah.

The council unanimously backed a French-drafted resolution after much wrangling with the United States over the mandate of the U.N. Interim Force in Lebanon (UNIFIL) tasked with monitoring a ceasefire between Hizbullah and Israel.

Hizbullah chief Sayyed Hassan Nasrallah on Wednesday defended a deal his group negotiated to evacuate Islamic State militants from the Lebanon-Syria border, saying it was the "only way" to resolve the "national and humanitarian" case of determining the fate of Lebanese soldiers captured three years ago by IS and later killed.

Nasrallah was responding to criticism of the deal, which was to allow over 300 militants and their families to relocate to an IS-held area in eastern Syria, near the border with Iraq.

The U.S.-led coalition has carried out an air strike to block Islamic State group fighters evacuated from Lebanon from reaching eastern Syria, its spokesman told the AFP news agency on Wednesday.

Hundreds of IS fighters were evacuated Monday from the border region between Lebanon and Syria under a ceasefire deal and were headed to an IS-held town near Syria's eastern frontier with Iraq. 

A U.S. official has blasted a deal that led to the evacuation of hundreds of Islamic State group fighters and civilians from the Lebanon-Syria border to areas close to Iraq, saying the extremists should be killed on the battlefield.

The evacuation agreement, the first such publicized deal, had already angered many Iraqis who accused Syria and Lebanon's Hizbullah of dumping the militants on the Iraqi border rather than eradicating them.

Buses carrying hundreds of Islamic State militants and their families arrived in eastern Syria on Tuesday following a negotiated evacuation from the Lebanon-Syria border, where the U.S.-backed Lebanese army deployed for the first time in years.

Lebanon has called for a U.N. peacekeeping force's mandate to be renewed without changes so that it can continue working to prevent hostilities between Israel and Hizbullah.