EL-ARISH, Egypt (Ma'an) -- Egyptian authorities seized 6,500 liters of fuel in northern Sinai that were headed to Gaza via underground border tunnels, security sources said.

Forces stopped three trucks in Bir al-Abed and detained two smugglers, while a third escaped, the sources said.

Gaza's only border crossing not controlled by Israel, Egypt's Rafah terminal, is not equipped for the transfer of goods.

The tunnels have been used to import anything from food to construction materials, fuel and cars, and militants have also used them to import munitions.

After turning a blind eye for years, Egypt started closing the tunnels after an Aug. 5 attack in Sinai when gunmen killed 16 Egyptian soldiers. Egypt suspects the tunnels were used by some of the militants, but Hamas says no one from Gaza was involved in the attack.