For the second time this month, NATO warplanes have accidentally bombed the Libyan rebel forces that were mistaken for Gadhafi regime troops. Today’s strike came in Misrata, and saw the warplane kill 12 rebels and wound five others.

The rebel commander said the strike came on a coastal salt factory, which rebels had seized and fortified as a defensive position. They insisted they told NATO about taken over the factory yesterday. NATO has yet to comment.

The previous incident came on April 7 in the Eastern city of Ajdabiyah, when NATO troops bombed tanks belonging to the rebel forces and killed at least 13. NATO was initially said to have apologized but later denied this, saying they had no idea the rebels even had tanks.

Misrata is the last western city under the control of the rebels, and has been contested by regime forces for weeks. The regime had stopped its attack for a day or so, and launched a surprise strike again yesterday, sparking a new battle.