Authorities in Bahrain said they seized explosives and materials for making bombs Thursday. The materials were intended for use in Bahrain and other Persian Gulf countries such as Saudi Arabia, they said.

According to police, it was an attempt to use Bahrain as a base for targeting major Gulf countries for extremist activities. Police Chief Maj. Gen. Tariq al-Hasan said in a statement that the techniques used in making the explosives were similar to those used by Iranian extremist groups such as the Islamic Revolutionary Guards.

“The professionalism with which these seized materials are assembled and concealed is a clear indication of international support and sponsorship,” Hasan said, as Reuters reported. “Of greater concern, however, is the fact that these sophisticated bomb-making materials were destined for Saudi Arabia, a sign that extremists are increasingly using Bahrain’s borders as a launchpad for terrorists seeking to carry out attacks elsewhere in the region.” Hasan added that a number of seizures in recent months pointed to an “emerging trend.”

Bahrain News Agency reported that an investigation revealed two names linked with extremist activities in Bahrain: Murtadha Majeed Ramadhan Al Sindi, 32, and Qassim Abdullah Ali, 26. These two fugitives in Iran formed a terrorist group to target the security of Gulf countries like Bahrain and Saudi Arabia, police said.

According to the police chief, the seized materials included advanced circuitry, commercial detonators, chemicals, mobile phones and the plastic explosive C4. He said that there was a “significant escalation” of efforts to smuggle explosives into the country.

Bahrain often blames Iran’s Shiite Muslim theocracy for trying to overthrow the Gulf Arab island monarchy. While Bahrain police indicate a link between the explosives and an Iranian proxy group, Iran has maintained its stance that it does not interfere in activities in Bahrain. However, it admits that it extends support for opposition groups fighting for economic and political rights for the Shiite Muslim community in Bahrain.

In recent years, there has been a significant increase in the use of homemade explosives in Bahrain. There was a seizure in the Dar Kulaib district June 6. There was another seizure in May when a vehicle carrying similar explosives was moving from Bahrain to Saudi Arabia.