Libyan army troops on Wednesday pushed into Benghazi, the first time in two months that government forces had entered the eastern city, which has been under control of Islamist militias.

Egypt’s military involvement in Libya underlines Cairo’s concerns about the threat posed by Islamic militant groups operating near the two nations’ porous border, as well as home-grown jihadis who rely on their Libyan comrades for weapons. Above all, Egypt aims to prevent these groups from linking up.

“This is a battle for Egypt not Libya,” one of the senior officials said. “Egypt was the first country in the region to warn against terrorism and it is also the first to fight it.”