Chad’s President Idriss Deby has taken a strong early lead and appeared poised to extend his 30-year rule, partial provisional results of the April 11 presidential election showed, as the United States and the United Kingdom warned of possible violence in the Chadian capital, Ndjamena.

The Independent National Election Commission (CENI) said on Saturday that Deby won a majority in all but one of the 51 departments announced so far, and secured a plurality in the other.

The UK government, meanwhile, said two convoys of a Libya-based rebel group were heading towards the capital. The convoys belonged to the Front for Change and Concord in Chad (FACT), which had attacked a border post in the north of the country on election day.