TIMELINE: Flashpoints and flare-ups in India-Pakistan ties

(Reuters) - Pakistani President Asif Ali Zardari telephoned India's prime minister on Friday to condemn attacks in the Indian city of Mumbai that killed at least 121 people and suggested "non-state actors" were responsible.

On Thursday, Indian Prime Minister Manmohan Singh pinned blame on militant groups based in India's neighbors, usually an allusion to old rival Pakistan, raising prospects of renewed tension between the nuclear-armed rivals.

Here is a timeline charting some key moments of tension between the two countries.

* August 14, 1947: Muslim Pakistan is formed from partition of India at end of British colonial rule, amid bloodletting between Hindus and Muslims.

* Oct 1947: The two countries fight their first war over Kashmir, after its Hindu ruler opts to join secular India rather than Islamic Pakistan.

* Jan 1949: U.N. Security Council-ordered ceasefire takes effect in Kashmir.

* September 1965: Second war over disputed Kashmir region. Combat ends after U.N. calls for ceasefire.

* December 1971: Third India-Pakistan war over East Pakistan. It ends with surrender of 90,000 Pakistani troops and leads to creation of Bangladesh, formerly East Pakistan.

* Dec 1989: Jammu and Kashmir Liberation Front rebels kidnap daughter of Indian home minister, demand five separatist leaders are freed for her release. The government gives in, in a move seen as a major boost for separatist groups.

* Jan 1990: Indian army kills 38 people in Srinagar, Kashmir's summer capital, during protest against crackdown on separatism. More than 40,000 people are reported killed in ensuing insurgency over the next 14 years. India says Pakistan arms and trains guerrillas. Islamabad denies the charge.

* May 1998: Soon after Hindu nationalist-led alliance takes power, India holds its first nuclear tests in Rajasthan, near Pakistan border. Pakistan responds with six tests.

* December 2001: Gunmen attack Indian parliament. India blames Pakistan-based Kashmiri militants, Pakistan denies this. India cuts air, rail and road links and pulls out diplomatic staff.

* Jan 2002: India masses hundreds of thousands of troops on border. Pakistan follows suit, raising specter of another war.

* November 2003: Pakistan announces ceasefire in Kashmir. India accepts and truce takes effect on November 26.

* June 2004: The two agree to set up nuclear hotline, renew ban on nuclear testing, re-open Karachi and Bombay consulates and restore size of New Delhi and Islamabad embassies.

* July 2006: Bomb blasts in India's financial capital Mumbai kill more than 180 people. Peace talks are canceled after Indian government blames Pakistan-based militants.