Iraqi security officials say a series of rockets exploded as bomb disposal experts attempted to defuse them, killing at least 15 people and wounding at least 27 others in Baghdad.

Police had found the rockets earlier Tuesday in the back of a truck that was believed to have been used by insurgents to launch an attack on a nearby U.S. military base. U.S. officials confirmed that attack.

The police say they had called in the bomb squad, which was working to disarm the rockets when they exploded. The authorities believe many of the dead were policemen.

Also today in Baghdad, An Iraqi court delayed the trial of two former officials accused of links to Shi'ite death squads.

The trial had been due to begin today but the proceedings were postponed until March 2 because some witnesses failed to show up.

The trial is the first involving high-ranking Shi'ite officials suspected of involvement in sectarian killings that erupted in Iraq two years ago.

The two defendants are Iraq's former deputy health minister, Hakim al-Zamili, and the former head of the health ministry's security forces, Brigadier General Hameed al-Shimmari.

They are accused of helping Shi'ite militiamen from the Mahdi Army use ambulances and hospitals to kidnap and kill their rivals.

In other news, the Iraqi government today announced it has agreed to buy 40 new aircraft from the U.S. manufacturer Boeing and six from the Canadian company Bombardier for Iraqi Airways. Media reports say the Boeing deal is valued at about $6 billion.

Some information for this report was provided by AFP, AP and Reuters.