A bill removing the age limit for the president was introduced in parliament last month, and MPs are currently holding consultations with ordinary Ugandans to seek their views.
“Consultations must not include illegal demonstrations, illegal processions, inciting violence, use of hate campaigns, use of abusive language, acts of hooliganism of any sort, intimidation of any persons perceived to be supporting the removal of the age limit,” the assistant inspector general of police, Assuman Mugenyi, said in a statement.
In Uganda, opposition demonstrations are routinely denied permission, meaning any rally is considered illegal.
Mugenyi ordered police to ensure MPs only hold consultations in their respective constituencies.
On Tuesday night police fired teargas and rubber bullets at a crowd of hundreds of opposition supporters protesting the age limit bill.
The current curbs would prevent Museveni, in charge for the last three decades, from running for a sixth consecutive term in 2021.
Museveni is aged 73, while the current law blocks candidates over 75.
The leader of the opposition in parliament Winnie Kiiza told AFP the police directive was “unconstitutional”.
“We are going to challenge it by all means,” said Kiiza.
It is unclear when the bill will come before parliament