An unidentified person hurled an explosive substance at a wall of the Communist Party of India (Marxist) headquarters in Kerala’s Thiruvananthapuram on Thursday night, PTI reported, citing the police.

The incident took place around 11.30 pm at the AKG Centre, where the building is located. The police said there were no casualties.

CCTV visuals showed a two-wheeler rider hurling the explosive substance at the building and fleeing from the spot.

Leaders of the CPI(M) alleged that it was a “bomb attack”, PTI reported. Some CPI(M) members who were at the AKG Centre when the attack took place said they heard a loud blast outside the compound.

The police were alerted and a bomb squad was deployed to inspect the site. Thiruvananthapuram Police Commissioner G Sparjan Kumar said an investigation has been initiated, ANI reported.

Senior CPI(M) leader and the ruling Left Democratic Front’s Convener EP Jayarajan blamed the Congress for the attack. He, however, appealed to the party workers to remain calm.

“The CPI(M) headquarters was attacked by Congress criminals,” said AA Rahim, the state committee member of CPI(M). “I condemn this attack and appeal to our cadre to hold a peaceful protest against it.”

Members of the CPI(M) on Friday held a march in the city to protest against the attack, PTI reported.

Meanwhile, the Congress party has refuted the allegations, reported The Indian Express.

“I won’t blame even CPI(M), Jayarajan is behind that attack,” said Congress state president K Sudhakaran. “AKG centre has police protection. Will any Congress worker dare hurl explosives there?”

Sudhakaran said the CPI(M) planned the attack in an attempt to divert the public’s attention from the “ruling party’s scandals”.

He was likely referring to the allegations that Kerala Chief Minister Pinarayi Vijayan had taken a bag full of currency to the United Arab Emirates in 2016.

“When Rahul Gandhi is visiting Wayanad on Friday, will any Congress worker attack the CPI(M) office to spoil the day?” he asked. “CPI(M) wanted to divert the attention from Rahul’s visit. Only a person familiar with AKG centre can carry out such an attack.”

Congress leader Rahul Gandhi is scheduled to visit his constituency Wayanad on Friday.