Abu Musab al-Zarqawi, the insurgent leader in Iraq, has been wounded, according to some militant Web sites, CNN reported on Tuesday.

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The message posted on these Web sites says that al-Zarqawi's comrades are proud of 'his heroic wounds' and that 'resistance [in Iraq against American forces] will get tougher'.

While the statement sounds similar to previous messages from al-Zarqawi's group, it doesn't bear the group's logo, CNN quoted Pentagon officials as saying.

The United States has announced a $ 25-million reward for information leading to the capture of al-Zarqawi.

The Web site did not mention how and when al-Zarqawi was wounded.