NEW DELHI, Thursday, Dec. 9 (Reuters)—Indian aircraft attacked Karachi harbor and city early today, sinking one merchant ship and killing Many. civilians, the Pakistan radio reported.

The radio said that a second ship had been set ablaze and a third, a foreign vessel, had been seriously damaged.

In an earlier attack during the night, Indian planes struck a petroleum storage tank near the harbor and set it on fire; the radio added.

In their second attack the Indian planes struck civilian targets in Karachi killing many people and destroying a number of houses in various areas, the radio said.