Abuja - Simmering tensions over a key oil-producing state in Nigeria mounted on Thursday, as the country's two main political parties traded threats and insults, stoking fears of violence in the run-up to elections.
The ruling Peoples Democratic Party (PDP) of President Goodluck Jonathan accused the opposition All Progressives Congress (APC) of issuing a "clear and direct call for anarchy" over its strongly worded comments about Rivers state.
The APC alleged the presidency had promoted and supported a "culture of lawlessness and impunity" in the southern Niger Delta state since last February and claimed its police commissioner was a "de facto military governor".
In a statement after a national executive committee meeting, it said police chief Joseph Mbu was doing the ruling party's bidding by cracking down heavily on peaceful APC rallies but doing nothing against similar PDP events.
If the situation continued, the APC warned it would have no option but to call on its members in Rivers and across the country "to take whatever steps that are necessary to protect their lives and property".
The party also urged its members in parliament to block government proposals, including last week's appointment of new defence chiefs and approval of the 2014 federal budget, "until the rule of law and constitutionalism is restored".
Nigeria, Africa's biggest oil producer and most populous country, has been fighting a bloody Islamist insurgency in the north of the country since 2009, which has claimed thousands of lives.
Presentation of the budget for 2014 was postponed several times late last year.
Secret police issues warning to 'subversive elements'
Nigeria's secret police, the Department of State Services (DSS), meanwhile issued a warning against those seeking to foment violence before the keenly watched 2015 vote.
No specific examples were given but it came just as the APC issued its comments.
DSS spokeswoman Marilyn Ogar called the statements "offensive, misguided and directed at stirring hate".
"This service and other law enforcement agencies have the mandate to protect the country and its citizens," she said.
"We therefore warn all subversive elements that are bent on promoting divisive and disruptive agenda to desist from such, as the full weight of the law shall henceforth be brought to bear accordingly."
Rivers's high-profile governor Rotimi Amaechi was one of five who defected from the PDP last November, in part over Jonathan's alleged refusal not to abide by an unwritten party rule to rotate the presidency between north and south.
Jonathan, who has not declared his candidacy for next year, comes from the majority Christian south while Nigeria's north is mainly Muslim.
A total of 37 lawmakers in the National Assembly followed the governors, stripping the PDP of its majority in the lower house of parliament and raising the possibility of its first general election defeat since Nigeria returned to civilian rule in 1999.
The outspoken Amaechi has also claimed Jonathan has done nothing for Rivers and is angered that millions of dollars in revenue from a disputed oil well has gone to the president's home state of Bayelsa next door.
In response, the PDP said the APC had shown its true colours and that its call to block approval of the new military top brass was a "devilish plot to undermine the nation's security, create a state of anarchy and... unleash mayhem".
By seeking to block the passage of this year's budget, it was also seeking to "cripple the nation's economy and plunge the people into untold hardship," said party spokesman Olisa Metuh.
In doing so, "the APC has commenced the implementation of its orchestrated plot to truncate the nation's democracy, push the country into a state of chaos and achieve its doomsday predictions; a plot which must be stopped", he added.