A video reportedly shows airline workers handing a bomb to the suspected Somali plane bomber

CCTV footage released by the Somali National Intelligence Agency (NISA) on Monday appears to show two airport workers inside the terminal of Mogadishu airport handing a suspected suicide bomber a laptop stuffed with explosives on February 2.

Somali officials said an investigation had been launched and arrests made, including airport workers who were said to be co-operating with authorities.

In total, Somali officials have said that over 20 people have been arrested over possible linkages to the bombing, including an unspecified number of airport workers.

The bomber was sucked out of a Daallo Airlines plane through a one-meter wide hole, when the blast ripped open the pressured cabin in mid-air last Tuesday.

The pilot was forced to make an emergency landing in the Somali capital, from where the plane had taken off.

No group has so far taken responsibility for the attack, but a U.S. government source last week said the United States suspects Islamist militant group al Shabaab, which is aligned to al Qaeda, was responsible.

In another twist, Daallo Airlines' chief executive confirmed on Monday that the bomber was meant to be on a Turkish Airlines flight, which was canceled due to bad weather.

Mohamed Yassin told Reuters the bomber was among 70 stranded Turkish Airlines passengers who were picked up to be flown to Djibouti with his carrier. In total, the flight had 74 passengers.

Turkish Airlines did not immediately respond to Reuters for a request for comment.

Somalia, mired in conflict since civil war broke out in 1991, has few air links outside East Africa. In 2012, Turkish Airlines became the first major international commercial airline to fly out of Somalia in more than two decades.

Mogadishu's heavily guarded airport, which is often compared to the Green Zone in Baghdad, has several safety perimeter fences and checkpoints. It houses a large U.N. compound along with several other Western embassies.

Al Shabaab, which wants to topple the government and impose a harsh version of Islamic law, has targeted the airport in the past. It has also attacked the Turkish embassy in Mogadishu. The group, which was pushed out of the last Somali city it controlled in 2012, still maintains the ability to carry out deadly attacks throughout East Africa.

On January 15, the group overran a Kenyan military base in southwestern Somalia, killing upwards of 60 soldiers. This was followed by an assault on a beach restaurant in Mogadishu on January 20 that killed an estimated 20 people.

If airport workers are proven to have been complicit in this bombing, this latest al Shabaab attack has chilling similarities to ISIS's bombing of a Russian airline over the Egyptian Sinai peninsula in October 2015. That bombing is believed to have been facilitated by an airline mechanic who planted a bomb on the Russian plane.