Two new arrest warrants were issued on Friday as part of an investigation in to the cause of the massive explosion which rocked Lebanon's capital Beirut on 4 August.
Friday's warrants were issued for Beirut's customs authority director, Hanna Fares, and Nayla Al-Hajj, an engineer who reportedly completed maintenance work on the port's warehouse 12, where the explosion originated.
The blast happened when 2,750 tonnes of ammonium nitrate, stored in Beirut port's warehouse 12 for six years prior to the disaster, ignited and exploded.
The explosion devastated the city causing widespread material damage, while killing nearly 200 and injuring thousands more.
Fare's and Al-Hajj's arrest warrants are the fifth and sixth to be issued by Fadi Sawwan, the judge leading the official investigation, since the enquiry was opened early last week.
The Director General of Beirut Customs Badri Daher and Director General of Beirut Port Hassan Qureitem are among those arrested as part of the probe. Both were placed under house arrest in the days immediately after the blast.
The six are part of a group of 25 people, including former and current ministers, facing legal action over their role in the blast.
Sawwan's jurisdiction to investigate, however, extends beyond the list to "anyone identified by the investigation as being a perpetrator, partner, interferer or negligent" in the explosion, according to a report by local outlet Naharnet.
Lebanon's investigation is being assisted by the US' FBI and other international foreign experts.
According to President Michel Aoun, the investigation is set to be conducted in sections and aims to establish three key points: the circumstances surrounding the cargo; where the ammonium nitrate came from and who shipped it; and to find those responsible for handling a securing it in Beirut.
Protesters, who have returned to the streets in the aftermath of the Beirut explosion, have blamed the government, which resigned less than a week after the blast, and called for independent international investigation. The idea, however, has been rejected by Lebanese officials.
Questions over the independence of the Sawwan's investigation, however, remain, with observers concerned the 60-year-old judge may cave to political pressure.
Despite planning to question former and current ministers as part of the probe, Sawwan cannot prosecute government office holders for crimes committed during their tenure.
Instead, the judge will have to refer politicians accused of negligence to the high council for presidents and ministers. Even then, two-thirds of parliament would have to agree to take the case forward, making it unlikely government officials will face justice.
Claims inaction by government ministers led to the Beirut explosion have been fuelled by documents, unearthed in the wake of the explosion, that allege top officials, including Aoun and now-caretaker Prime Minister Hassan Diab, were aware the highly explosive substance was stored in Beirut's port but failed to take preventative action.