BEIRUT, August 6. /TASS/. The Supreme Defense Council of Lebanon, which convened for an emergency meeting on Tuesday night, declared the country’s capital Beirut a disaster-stricken city following a powerful blast in the seaport.

"The defense council decided to declare Beirut a disaster-stricken region and declare the state of emergency for the period of August 4-18," said the press service of Lebanese President Michel Aoun, who chaired the meeting.

"The Defense Council resolved to set up a special commission to investigate the disaster, which is to prepare its report within the next five days," the press service said in a statement.

Al Jazeera quoted Prime Minister Hassan Diab as saying that an investigative commission should be established and publish its findings within 48 hours.

Diab also said it was inadmissible that 2,750 tonnes of ammonium nitrate had been stored in the port for six years, without necessary precautions being taken.

In his words, the government would focus on search for survivors and removal of the dead from the debris.

A powerful blast rocked the Beirut seaport district on Tuesday, sending a shockwave that ripped through residential areas of the Lebanese capital. The shockwave destroyed and damaged dozens of buildings and cars. According to first reports, the tragedy was caused by the detonation of 2,700 tonnes of ammonium nitrate during welding works.

A TASS correspondent learned from sources in the Lebanese capital that the explosive cargo was stored in the port after being confiscated from a Moldovan vessel with Ukrainian crew in 2015.

Strong signals from the blast were detected by infrasound stations of the Comprehensive Nuclear-Test-Ban Treaty Organization’s International Monitoring System (CTBTO IMS) in Tunisia and Germany.

"CTBTO IMS detected strong signals from large explosion in Beirut today 4 August 20 ~15:05 UTC at infrasound stations I48TU Tunisia & I26DE Germany. Analysts continue to review all data. Our thoughts go to the many victims caused by the explosion - Solidarity with Lebanon," Executive Secretary of the Comprehensive Nuclear-Test-Ban Treaty Organization Lassina Zerbo said on Twitter.

According to latest reports, 78 people were killed and some 4,000 injured in the disaster. An effort to search for victims and remove debris is now under way. The government declared a four-day nationwide mourning.