The UN staffer who disappeared several days ago in the Syrian Golan Heights is a Canadian citizen working with the UN peacekeeping mission there, sources familiar with the missing man told The Times of Israel.

Carl Campeau, a Canadian legal adviser, was stationed at the United Nations Disengagement Observer Force base on the Syrian side of the demilitarized zone separating Israel and Syria until he went missing several days ago. Attempts by The Times of Israel to contact Campeau on his cell phone and at his office were unsuccessful.

The UNDOF spokesperson refused to respond to inquiries by The Times of Israel concerning the missing staff person.

The Canadian Embassy in Israel responded to an inquiry regarding Campeau saying, “We are pursuing all appropriate channels to seek further information.”

The embassy would not officially confirm that Campeau was the missing UN staffer.

Canada officially withdrew its contingent from the peacekeeping force on the Syrian border in September 2012.

The United Nations confirmed Monday that a member of the UNDOF staff was not accounted for and that the UN was “in touch with the relevant parties to determine what has happened.”

It didn’t reveal any further information about the individual’s identity.

The Times of Israel earlier Monday quoted a rebel activist reporting that President Bashar Assad’s army has fled the Golan Heights area bordering Israel, and that rebel forces are in control there.

The UN force, UNDOF, was established in 1974, following the 1973 Yom Kippur war. Israel captured the Golan Heights from Syria in 1967 and Syria has agitated to have the land returned.

UN Secretary-General Ban Ki-moon has warned of escalating military activity along the Israeli-Syrian border as a result of the intensifying Syrian conflict, which has gone on for two years and cost more than 70,000 lives.

In December, Ban accused the Syrian government of serious violations of the 1974 separation agreement and called on both countries to halt firing across the cease-fire line. He also cited numerous clashes between Syrian security forces and opposition fighters in the disengagement zone.

In response, he said, UNDOF has adopted a number of security measures.

The Israel Defense Forces declined to comment.

AP contributed to this report.