BEIRUT (AP) — Syrian rebels fighting to topple President Bashar Assad say the Damascus International Airport is a “legitimate target.”

Friday’s announcement is a stern warning to the regime and travelers planning to use the airport.

It comes as fighting between Assad’s troops and rebels intensified near the airport just south of the capital. Clashes in the area forced the closure of the airport road for the second time this week.

The fighting has also forced the suspension of commercial flights in the past week.

Two fighters operating in the capital’s southern suburbs say the rebels are trying to besiege the airport in an attempt to cut military supplies to the regime.

The two spoke on condition of anonymity for security reasons.