Nigeria is facing an escalating political crisis after President Bola Tinubu declared a state of emergency in the oil-rich Rivers state and suspended the governor, his deputy and all lawmakers in the state parliament for six months.

In a nationwide broadcast on Tuesday evening Tinubu said he had received "disturbing security reports detailing incidents of vandalisation of pipelines by some militants without the governor taking any action to curtail them".

He added that he could not allow the "grave situation" to continue.

But lawyers and opposition politicians are questioning the legality of the president's decision.

Tinubu made the announcement after one of the country's highest producing crude oil pipelines, the Trans-Niger Pipeline, suffered significant damage due to a blast.

Attacks on pipelines have in the past been carried out by criminal gangs or militants, halting production and exports.

At current prices, the oil flowing through the affected pipeline fetches around $14m (£11m) a day, according to the online publication Africa Report.

But against the backdrop of the blast, there has been a political rift in Rivers state that has reached boiling point.

Governor Siminalayi Fubara is a member of the People's Democratic Party (PDP) which has been plagued by reports of in-fighting. At a national level, the PDP is the main party opposed to the president's All Progressives Congress.

Tinubu said that politicians have not been able to work together effectively because of the ongoing turmoil. He alleged that allies of Fubara had threatened "fire and brimstone" against the governor's enemies and that they had not "disowned" these comments.

Rivers state lawmakers had threatened to impeach the governor and his deputy, according to Reuters news agency.

Tinubu said this political crisis has left Rivers state at a "standstill" adding that this latest measure is based on the need to restore peace and order to the state.

Fubara gave a measured response to the state of emergency.

He said there have been "political disagreements, but good governance has continued".

"Rivers state is safe, secure and peaceful under our watch," he said.

The state of emergency will allow the government to run the state in the interim and send security forces if needed.

But many groups see Tinubu's action as draconian.

The Nigerian Bar Association (NBA) said it was "unconstitutional" to remove an elected governor, deputy governor, or members of a state's legislature.

The PDP rejected the emergency rule, calling it an attempt at "state capture". It accused Tinubu of trying to turn Nigeria into a one-party country.

"It is the climax of a well-oiled plot to forcefully take over Rivers state," it said.

Peter Obi, a former presidential candidate for the Labour Party, criticised the move which he described as "reckless" on X.

This is not the first time a state of emergency has been declared in Nigeria. Former presidents resorted to the action in a bid to curb insurgency and instability in different parts of the country.

Additional reporting by Nkechi Ogbonna