Thatcher, who headed the British government during the hunger strike that killed Bobby Sands, a member of the British Parliament, and nine other republican prisoners, was an even more divisive figure in the province than she was in England and Scotland. The province has already seen some demonstrations since her death last week.
Stephen Cargin, chief superintendent of the Police Service of Northern Ireland, said Monday extra officers would be sent to Londonderry Wednesday to prevent violence during the funeral, the Belfast Telegraph reported.
"It is clear that there are elements out there encouraging our young people to get mixed up in violence and disorder," Cargin said. "They are putting young people at risk and causing damage within the local community. Parents need to take an active interest in what their children are doing."
On Saturday, a group in the majority-Catholic Cliftonville neighborhood in Belfast paraded with a mock coffin topped with a witch's hat before a soccer match. Nigel Dodds, a member of Parliament representing North Belfast and member of the Democratic Unionist Party, called the action "disgusting and distasteful," the BBC said.
Northern Ireland Sports Minister Caral Ni Chuilin, a member of the republican Sinn Fein party, also condemned the demonstration, the Telegraph said. She said while Thatcher brought "misery, humiliation and degradation to this country," protesters should behave in a dignified way.
"They shouldn't follow in her footsteps," Ni Chulin said.
Political tensions were already running high. The Belfast City Council's vote in early December to limit the day on which the British flag will be flown at city hall was followed by weeks of violent loyalist demonstrations, while dissident republican groups have been involved in a number of bombings or attempted bombings.