TIMELINE: Tensions between Sudan and Chad

(Reuters) - Darfur rebel leader Khalil Ibrahim said on Monday he would launch more attacks on Sudan's capital Khartoum until the government fell.

Sudan has said neighboring Chad was backing the rebels.

Here is a chronology of recent Chad-Sudan tensions:

Jan/Feb 2004 - Thousands of refugees from Sudan's Darfur region arrive in Chad fleeing government bombings and raids by Arab Janjaweed militias.

April 9 - Chad brokers a ceasefire between the Sudanese government and two Darfur rebel groups.

April 11, 2005 - Chad suspends mediation, accusing Sudan of supporting Chadian rebels. It returns to mediation after promises from Khartoum that it would act against the rebels.

December 18 - Chad says its forces killed about 300 rebels after they launched a failed offensive on the border town of Adre. Sudan denies involvement.

Jan 8, 2006 - Chad demands Sudan disarm Chadian rebels in Darfur as a condition for peace talks.

Feb 8 - Chad and Sudan agree to put an end to their dispute at a meeting in Libya.

April 13 - Chad government forces fight off attack by rebels on the capital N'Djamena. Several hundred people killed. Deby breaks diplomatic relations with Sudan the next day.

July 26 - Chad and Sudan revive their deal in Libya to defuse tension on the border.

Aug 8 - Chadian President Idriss Deby and Sudanese President Omar Hassan al-Bashir agree to restore ties.

Feb 1, 2007 - Rebels fighting to overthrow Deby launch an attack on Adre, before being beaten back.

Feb 22 - At a conference in Libya, leaders of Sudan and Chad pledge to redouble efforts to end border violence, concluding their third agreement in a year.

May 3 - Sudan and Chad sign a Saudi-brokered reconciliation deal in Riyadh, requiring both sides to cooperate with the U.N. to stabilize Darfur and the adjacent region in Chad.

Oct 25 - Chad and four Sudan-based Chadian rebel groups sign a "definitive peace accord" in Libya. At least two groups later abandoned the accord.