NAIROBI, Kenya — Somali pirates attacked on oil tanker today farther out at sea than any previous assault, suggesting pirate capabilities are growing as they increase activity off East Africa.

Pirates in two skiffs fired automatic weapons and rocket-propelled grenades at the Hong Kong-flagged BW Lion about 1,000 miles east of the Somali coast, the European Union Naval Force said.

The tanker's captain increased speed and took evasive maneuvers, avoiding the attack, the force said. No casualties were reported. The naval force sent a plane from the Seychelles islands to investigate.

Pirates have launched increasingly bold attacks against vessels in the Indian Ocean and Gulf of Aden in hopes of capturing a ship and crew and collecting ransom. They currently hold more than 190 hostages, including a British couple seized from their personal yacht late last month.