Experts are warning that high sea piracy is making a comeback in the Indian Ocean along the Somali waters posing a security threat for vessels fishing or plying the east African coast line.

Piracy along the Somalia coast had subsided in the last three years mainly due to shipping firms hiring private security details and increased patrols by international warships, but it’s making a comeback as the level of illegal fishing rise along the horn of Africa waters.

According to a Reuters report, Somali pirates hijacked an Iranian fishing vessel with 15 crew member on Sunday evening, while another Thai trawler managed to escape following an attempted hijacking on Monday in waters off central Somalia.

Other ships plying the route have also reported increased attacks in the past week. There were another two unsuccessful attempts this month, CNN reported.

Somalis have often complained that foreign trawlers illegally fish along the country’s coast threatening the livelihoods of fishing communities in the war-torn country.

“The level of illegal fishing is prompting these sort of attacks, and the potential for bringing piracy back,” John Steed from Oceans Beyond Piracy, which monitors piracy and runs a support program to help hostages,  told AFP.

Piracy along Somalia’s coast was at its worst in 2011, when more than 700 people were taken hostage for ransom. At the moment fewer than 40 hostages are still in pirate hands, including 26 Asian crew members from the fishing vessel Naham 3, who have been held for more than four years.

A fall in piracy in recent years and a reduction in international naval patrols has exposed shipping companies that are overstepping in to Somalia waters to attacks along the coast.

According to a recent UN report increased “illegal, unreported and unregulated fishing by foreign vessels may re-establish the conflict dynamic with local fishing communities that contributed to the rise of piracy a decade ago”.

“There is more scope for the pirates to find a target,” Steed said. “The potential is quite high for Somalia’s piracy problem to come back altogether if we are not very careful.”