Uganda's central bank sold dollars on Monday after the shilling fell in early trading to test the key 2,400 per dollar level, possibly in reaction to last week's riots, traders said.

"I believe the central bank did not want the shilling to tumble to the 2,400 area which it was threatening," said Lucas Ochieng, a trader at Orient Bank Uganda. "It could have been a reaction to the unrest that happened last Friday."

At 1050 GMT, after the intervention, the shilling was quoted at 2,374/84 per dollar, marginally stronger than Friday's 2,380/85 close. Earlier, the currency had weakened to 2,390/2,395, traders said.

The Bank of Uganda was not immediately available for comment.

"The central bank has intervened and sold dollars today," said Mark Bitarabeho at Standard Chartered Bank Uganda.

Two people were killed on Friday and at least 90 injured across the Ugandan capital as police fired bullets and teargas at crowds protesting against the arrest of an opposition leader.

Analysts say fears of a continuation of the unrest and potential economic disruption could hurt the shilling and hamper investment in Uganda.