Gaza, ALRAY - Egypt's closure of tunnels and Israel's ban on shipping building materials into the Gaza Strip left more than 70.000 construction workers, professionals and engineers jobless, the Palestinian contractors union said on Sunday.

Nabil Abu Muailaq the Director of the union told ALRAY that 30,000 workers in various economic sectors have been affected directly and another 40,000 were affected indirectly due to this siege .

He pointed out that the construction and service sectors and industries depending on them, such as craft workshop and transportation equipment stopped working as a result of the siege and closure imposed on the enclave.

He made clear that 95 percent of construction companies are completely cracked and 5 present are still working at Qatari and UN projects .

The construction sector is considered the biggest one that employs workers and contributes in 27 percent of GDP which is about 135 million dollars during the second quarter of 2013.

Israel froze shipments of building materials to the Gaza Strip after discovering an alleged "terror tunnel" entering its borders from the adjoining territory.

The Gaza Strip has been under a severe economic blockade imposed by Israel since 2007.

The blockade was imposed following the victory of the Hamas in the 2006 Palestinian elections and the subsequent 2007 events.

The blockade has severely limited the imports and exports of the Gaza Strip and has led to frequent humanitarian crises and hardship for Gazans.