Pakistani officials say bombs have exploded near two buses carrying navy personnel in Karachi, killing at least four people and wounding more than 50 others.
Authorities said the remote-controlled blasts Tuesday happened minutes apart in different areas of the southern port city.
The Taliban claimed responsibility for the attacks and vowed more strikes against security forces in the future.
Victims of the blasts included naval officers and other employees of the navy.
Karachi is Pakistan's economic hub and its largest city with roughly 16 million people. The city has been plagued by criminal, sectarian and militant violence.
Last week, a bomb blast at a gambling club in the Ghas Mandi area of Karachi killed at least 15 people and wounded more than 35 others. Police said they suspect criminal gangs were responsible for the attack.
Elsewhere, officials in Baluchistan province say armed men attacked a passenger bus late Monday and set it on fire, killing at least 14 people. Several women and children are among those killed in the attack.
Some information for this report was provided by AP and AFP.