Beirut Explosion: Death Toll Climbs to 135

A number of Beirut port officials are being placed under house arrest pending an investigation into Tuesday's huge explosion, Lebanon's government says.

The blast killed at least 135 people and injured more than 4,000 others. A two-week state of emergency has begun.

President Michel Aoun said the blast was caused by 2,750 tonnes of ammonium nitrate stored unsafely in a warehouse, BBC reported.

Customs chief Badri Daher said his agency called for the chemical to be removed, but "this did not happen".

"We leave it to the experts to determine the reasons," he said.

Ammonium nitrate is used as a fertilizer in agriculture and as an explosive, BBC reported.

Opening an emergency cabinet meeting on Wednesday, President Aoun said: "No words can describe the horror that has hit Beirut last night, turning it into a disaster-stricken city".