With the successful capture of the ancient city of Palmyra by the Islamic State of Iraq and the Levant (ISIL), the radical group now controls approximately 95,000 sq. km. of land, which is almost half the size of Syria. ISIL has tightened its grip on the historic city, prompting residents to fear for their lives.

ISIL said in a statement that the group was now in full charge of the historical site, including all of its military installations, according to Reuters.

Activists in Palmyra, who wished to remain anonymous, said the group took full control of the city on Wednesday, according to Al Jazeera. They added that despite the attempts to escape, many were left stranded on the streets.

"ISIL have infiltrated the city overnight. Power is down and we barely have any electricity or water. There is fear among residents and we do not know what to expect next," one of the activists said.

U.N. human rights spokeswoman Ravina Shamdasani said that tensions in the city are at an all-time high, as ISIL has now begun its search for civilians who are suspected of being loyal to the government, Reuters reported.

"ISIL (Islamic State) has reportedly been carrying out door-to-door searches in the city, looking for people affiliated with the government," she said.

"At least 14 civilians are reported to have been executed by ISIL in Palmyra this week," she added.

Activists and journalists in the city told Al Jazeera that civilians are having a hard time leaving the city and that government forces are not providing a way for them to escape.

"There are almost 170,000 people here, including 50,000 internally displaced people from Homs and Der Ezzor," one of the journalists in the city said.

"ISIL is hated by residents here and labelled terrorists," he added. "ISIL will not treat us any different than those elsewhere in areas they control. This is a new siege."

Reports of ISIL forces entering the city's ancient sites have surfaced, though there are currently no reports of destruction of the ancient ruins.