TEHRAN, Iran — President Mahmoud Ahmadinejad struck a defiant yet vague tone on Sunday, telling Iranians during the 28th anniversary of the Islamic Revolution that their country would not give up uranium enrichment but was prepared to negotiate.

BAGHDAD, Iraq — High-tech roadside bombs that have proved particularly deadly to American soldiers are manufactured in Iran and delivered to Iraq on orders from the “highest levels” of the Iranian government, a senior intelligence officer said Sunday.

A suicide bomber has killed at least 15 people and wounded at least 25 others at a police station north of Baghdad.