At least two Americans have been killed in the attacks, and five hostages were found dead at the Chabad center. The death toll now stands at 143.
Indian commandos are still battling pockets of resistant militants, with heavy fighting at the Chabad center yesterday and continuing at Taj Mahal hotel today.
The attacks are certain to complicate U.S. efforts to improve relations between India and Pakistan.
One Indian minister openly blamed Pakistan for "some elements" of the attacks.
Pakistan's intelligence chief will visit India to assist the investigation.
Several experts say the attacks resemble those conducted by two networks of Pakistan-based Muslim extremists. There are unconfirmed reports that British nationals were among the militants arrested.
A commentator notes that the attacks came on the eve of provincial assembly elections, describing the polarizing effect of India's religious factionalism and criticizing the government's counterterrorism efforts.
Victims relate harrowing tales of survival.
The Bombay Stock Exchange is rattled.
--Suzy Khimm