NAIROBI, Kenya (AP) _ A Sudanese rebel leader accused the government today of using a cease-fire to deploy additional troops and quiet allegations it had used chemical weapons against two rebel-held towns.

Col. John Garang of the Sudan People's Liberation Army said the government's announcement of a cease-fire Thursday was aimed at buying time to deploy thousands of army recruits who completed military training last week in Sudan, Africa's largest country.

``You cannot be graduating 70,000 forces and then say 'cease-fire,''' Garang told reporters in Kenya's capital, Nairobi.

Sudan's Ministry of Foreign Affairs, however, said the government was suspending fighting to facilitate ``the flow of relief operations.''

The rebel leader also said Friday the government was trying to counter bad publicity stemming from a U.N. decision earlier this week to investigate reports that the government dropped chemical bombs on two rebel-held towns in southern Sudan.

The SPLA has said Sudanese military planes dropped chemical or biological bombs on Lainya and Kaaya near Uganda's border on July 23. The government has denied using chemical weapons.

Garang also said government planes on Wednesday bombed Yei and Lainya, the largest town in southern Sudan held by the rebels. His claims could not be independently confirmed.

The SPLA announced a unilateral cease-fire on July 20 to permit delivery of relief food.

The cease-fire declared by the government was to take effect at midnight Thursday and expire on Oct. 15.

More than 1.9 million people have been killed in Sudan's civil war and war-related famines since the war began in 1983.

The rebels are fighting Sudan's central Muslim-dominated government, seeking autonomy and a greater share in the country's wealth for the south, where people are predominantly Christian or animists.