(CNN) -- Somali pirates have seized two vessels, the International Maritime Bureau said Tuesday.
The UK-flagged chemical tanker St. James Park, with 23 crew members aboard, was attacked at 14:49 UTC Monday (9:49 a.m. ET), said Michael Howlett, spokesman for the Maritime Bureau.
The vessel was hijacked in the Gulf of Aden, the European Union Naval Force in Somalia said on its Web site.
Twenty-six crew members were aboard -- including Bulgarians, Filipinos, Georgians, Indians, Poles, Romanians, Russians, Turks and Ukrainians, the EU naval force said.
After the vessel sent a distress signal, a warship from Task Force 151 contacted the ship and confirmed that it had been hijacked.
The St. James Park started its journey Sunday and is now heading toward the Somali coast, the EU naval force said, adding that it is monitoring the situation.
A second vessel, the Navios Apollon bulk carrier, sailing under Panamanian flag and carrying 19 crew members, was attacked at 18:47 UTC Monday (1:47 p.m. ET).
The bulk carrier also was seized in the Gulf of Aden off Somalia, Howlett said.
The Navios Apollon is owned by a Greek company, Howlett said, declining to disclose its name. He would not offer any details about the owner of the St. James Park, in line with the organization's policy.
The Maritime Bureau had no immediate information about the ships' cargo or destinations.