Secretary-General Ban Ki-moon warned Monday that the recent upsurge in fighting in Darfur could affect the success of upcoming political negotiations to end the four-year conflict in the vast western Sudanese region. Ban said he was «alarmed» that the reported attacks took place after the Sudanese government said in a joint communique during his visit earlier this month that it was committed «to a full cessation of hostilities in Darfur» in the run-up to the new negotiations in Tripoli, Libya, starting Oct. 27. «The secretary-general strongly urges all parties to show restraint and cease all military action in order to create a positive atmosphere for the envisaged political negotiations,» U.N. spokeswoman Michele Montas said. Ban returned from a trip to Sudan, Chad and Libya a week ago, during which he announced the date and venue of the peace talks and pushed for the speedy deployment of a 26,000-strong joint African Union-U.N. peacekeeping force to replace the beleaguered 6,000-strong AU force now in Darfur.