The boat would be used as a "mother ship" by its captors to launch further attacks, Ali Shire, mayor of the town of Haabo, told Reuters
The region had seen a steady decline in piracy over recent years, after gaining notoriety for the frequency of attacks around the turn of the decade. In 2010, Somali pirates hijacked 49 ships and took over 1,000 hostages, according to the International Maritime Bureau
There are mounting concerns that the period of relative calm may be over, and the threat from piracy could increase further.
A recent report
from the NGO Oceans Beyond Piracy (OBP) found that piracy is spreading and evolving.
Beyond the HRA, attacks surged off the West Coast of Africa with 95 incidents in 2016, up from 54 in 2015. The majority took place in Nigerian waters.
The report also noted a sharp rise in kidnap for ransom attacks in the region, with 96 hostages taken compared with 44 the previous year, but just a single instance of hijacking for cargo. Economic losses through piracy in West Africa increased by more than 10 percent to $793.7 million.
"The increase in kidnap and ransom attacks is troubling as they tend to entail greater violence," said report co-author Maisie Pigeon.
"They involve less risk to the pirates themselves and can produce lucrative returns."
Kidnap attacks also increased in Asia, where pirates took 67 hostages and killed six seafarers in 2016.
The Somali coast was relatively quiet last year, with no successful hijackings. But the report noted that the vigilance of vessels in the area had decreased, which Pigeon believes played a part in the spate of attacks in 2017.
"The perception of risk to shipping decreased, which gave pirate groups the opportunity to commit attacks," she says. "In East Africa, the intent and capability to attack has never gone away. Now we're seeing opportunities return."
Piracy authorities are concerned that the threat is escalating.
"What looked like one-off attacks on vessels is now looking more like a concerted and organized effort to attack shipping," says Alan Cole, head of Global Maritime Crime at the UN Office on Drugs and Crime.
Cole believes that carelessness has stoked the threat, with vessels failing to adhere to the best practices document BMP4
, issued by a group of leading maritime authorities.
BMP4 encourages vessels to register with the Maritime Security Centre Horn of Africa (MSCHOA) before entering the HRA, to report to a military liaison daily while in the area, and to implement protection measures such as lookouts and physical barriers to boarding.
The document also carries guidance for routes and speed, such as remaining within the International Recommended Transit Corridor (IRTC) that is protected by military support vessels from the European Union Naval Force (EU NAVFOR) and NATO.
The case of Aris-13, taken by pirates on 13 March near the Yemeni island of Socotra, highlights the need for such measures.
"The Aris-13 is a little oil tanker that was hijacked while cutting corners through a no-go area," says Chris Farrell, group commercial director of private security group Neptune Maritime Security. "(The ship) had a low freeboard, no armed guards, no razor wire and no deterrent."
Farrell says that just 77 percent of ships used the protected IRTC route last year, and 34 percent used armed guards -- significantly lower figures than previous years.
There is broad agreement among piracy experts that complacency has contributed to the current surge. But adhering to BMP4 alone is unlikely to resolve the issue long term.
Farrell points to a lack of co-ordination between naval fleets and security forces such as EU NAVFOR, which have a range of remits and priorities including prevention of drug smuggling and people trafficking.
He adds that pirates often receive light sentences for their crimes, which have little deterrence value.
Dr. Afyare Elmi, a political scientist at Qatar University who has published several papers on piracy, believes that conditions on land must be addressed.
"We have been relying on offshore containment, but the best way to combat piracy is through onshore solutions," he says. "The best way is to invest in the national government, to build capacity at national level."
A strong Somali government would be able to maintain effective policing and coast guard services, he argues, and implement new counter piracy legislation. Such a government could also be a valuable partner for international bodies, which have limited co-ordination with the current regime that is seen as weak and ineffective.
Beyond this, Elmi would like to see causes of piracy addressed such as poverty -- the country is wracked by famine
- and illegal fishing. He hopes for international assistance to prevent the plundering of Somali fish stocks, which is often cited as a grievance
Such longstanding, deep-rooted issues will not be easily resolved. But if the current wave of piracy continues, it could focus minds on Somalia's plight.