Protesters clashed with Lebanese security forces at anti-government demonstrations in Beirut on Thursday.
Officers deployed tear gas on dozens of people near parliament.
Demonstrators were angered by Tuesday's devastating blast, which officials say was caused by 2,750 tonnes of ammonium nitrate stored unsafely since 2013.
Many in Lebanon say government negligence led to the explosion, which killed at least 137 people and injured about 5,000 others.
The explosion destroyed entire districts in the capital, with homes and businesses reduced to rubble. Dozens of people are still unaccounted for.
The state news agency says 16 people have been taken into custody as part of an investigation announced by the government this week.
Since the disaster two officials have resigned. MP Marwan Hamadeh stepped down on Wednesday, while Lebanon's ambassador to Jordan Tracy Chamoun stepped down on Thursday, saying the disaster showed the need for a change in leadership.
Earlier on Thursday, French President Emmanuel Macron also visited the city and said Lebanon needed to see "profound change" from authorities.
He also called for an international investigation into the disaster.
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A city of sirens, empty buildings and empty streets
By Quentin Sommerville, BBC News, Beirut
This port was Lebanon's lifeline to the whole world. Something like 80% of the country's grain came through here. The grain silos, which were built way back when, are teetering. Just beyond there I can see a ship listing heavily. I've lived in Beirut for five years and it's almost unrecognisable – it's a city of sirens, of empty buildings, of empty streets.
As I look at the neighbourhood of Gemmayze just behind the port, I can't see a single pane of glass left. Entire roofs have gone – I can see friends' apartments which are just open to the sky now. All of this area, which was really heavily populated, has been abandoned. No-one is coming back here any time soon.
What's really noticeable as you walk the streets here is that every second person seems to have a broom in their hand. There are clear-up teams everywhere, but it's pretty low tech: tiny teams of people with pans and brushes to clean up an an entire city's devastation.
The thing that really strikes me is how enormously stupid it was, what criminal negligence it took to leave this highly explosive material right in the very heart of this city, within yards of people, their homes, their businesses. And the authorities here knew – they had been warned that these chemicals were dangerous and that they were a great risk to Beirut and Lebanon.
What triggered the explosion?
The ammonium nitrate – which is used as a fertiliser and as an explosive – had been in a warehouse in the port for six years after it was unloaded from a ship impounded in 2013.
The head of the port and the head of the customs authority said that they had written to the judiciary several times asking that the chemical be exported or sold on to ensure port safety.
Port General Manager Hassan Koraytem told OTV they had been aware that the material was dangerous when a court first ordered it stored in the warehouse, "but not to this degree".
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The ammonium nitrate arrived on a Moldovan-flagged ship, the Rhosus, which entered Beirut port after suffering technical problems during its voyage from Georgia to Mozambique, according to Shiparrested.com, which deals with shipping-related legal cases.
The Rhosus was inspected, banned from leaving and was shortly afterwards abandoned by its owners, sparking several legal claims. Its cargo was stored in a port warehouse for safety reasons, the report said.
More on the explosion in Beirut
What is the latest on rescue efforts?
A French rescue team working in the city said there was still a good chance of finding survivors, two days after the explosion.
One unnamed rescuer told Mr Macron that they hoped to find a group of seven or eight people believed to be trapped in a "control room" under the rubble.
Earlier media reports that a father-of-two, Amin Zahid, had been rescued from the sea on Thursday morning have been thrown into doubt after comments under an Instagram account set up to help families locate missing people suggested that the man pulled from the sea was not him. A new account appealing for information about Mr Zahid has been set up.
Security forces have sealed off a wide area around the blast site.
Public Health Minister Hamad Hassan said Lebanon's health sector was short of beds and lacked the equipment necessary to treat the injured and care for patients in critical condition.
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