Suspected Somali pirates have hijacked two European-owned tankers within 24 hours in the highest-profile strikes since foreign navies deployed en masse to the region's busy sea lanes, Reuters reported. "These are the biggest attacks this year. The pirates are showing they are very much alive," said Andrew Mwangura of the East African Seafarers Assistance Programme, which monitors piracy in the region from the Kenyan port of Mombasa. The 9,000-tonne MT Nipayia, a Greek-owned and Panama-registered ship with 19 crew on aboard, was taken on Wednesday 450 miles east of Somalia's south coast, the European Union and NATO said on piracy-monitoring websites. The 23,000-tonne MT Bow Asir, a Norwegian-owned and Bahamian-registered ship, was seized on Thursday 250 miles east of the south Somali coast, they said. The attacks show that Somali pirate gangs remain undeterred by a flotilla of ships from Western and Asian countries patrolling to try to prevent a repeat of last year's unprecedented wave of hijackings.