Investigators said there could be a link but other motives were not being ruled out.
According to an initial investigation, four men on two motorcycles threw two iron petanque balls and firecrackers at the security booth in front of the head office of Thai Rath about 3.20am. Two security guards were slightly injured.
The guards alerted police after two motorcycles showed up at the entrance and a man ran to the front gate and threw firecrackers at the booth.
The attacker, believed to be in his late 20s, was wearing a black jacket and blue jeans. The attack shattered the booth's glass window.
The attackers were believed to have fled in the direction of the Lat Phrao intersection.
Police found one ball inside the booth and another on the nearby road. They will examine the balls for fingerprints.
Metropolitan Police Division 2 chief Suthee Nerakanthee said police are still gathering evidence and little has emerged so far.
"It could be the work of a third party who just wants to stir up trouble,'' he said.
The attack comes at the height of a feud between the mass-circulation paper's cartoonist Somchai Katanyutanan, better known by his pen name Chai Ratchawat and supporters of Prime Minister Yingluck Shinawatra.
Mr Somchai posted a photograph of Ms Yingluck delivering a speech in Mongolia on his Facebook page, with the caption saying a bad woman is going everywhere selling out the country.
It caused an uproar among red shirts, who gathered in front of Thai Rath's head office on Vibhavadi-Rangsit Road to demand action be taken against the cartoonist.
Pol Maj Gen Suthee said security surveillance cameras at the Thai Rath office were being serviced at the time of the attack. Bang Sue police station superintendent Sunthorn Kongklam said police have reviewed footage from surveillance cameras in the neighbourhood but found nothing suspicious.
The attack on the country's largest daily newspaper has drawn the interest of national police chief Adul Saengksingkaew.
Pol Gen Adul called a meeting with senior police officers, including deputy chief of Metropolitan Police Bureau Prinya Chansuriya and Ordnance and Explosives Disposal officers.
Pol Maj Gen Prinya said officers are interviewing witnesses for more information about the attackers. He said the attack was intended to "scare'', not kill.
The Thai Journalism Association (TJA) Saturday issued a statement condemning the attack on the head office of the mass-circulation daily.
In its statement, the TJA said the attack was a deliberate act of press intimidation.
It called on those who feel they are unfairly treated to take legal action or seek help from the Press Council, which oversees media ethics, instead of carrying out vigilante attacks.
The Pheu Thai Party Saturday dismissed speculation that red-shirt supporters might have been involved in the incident.
Deputy spokesman Anusorn Iamsaard said he did not think the attackers were the red shirts who recently protested outside the newspaper's offices.
He said although Pheu Thai and the party's supporters are upset with Mr Somchai's comment about the prime minister, they have respect for Thai Rath as it is a longstanding media institution.
He joined the TJA in denouncing the attack and promised that the Pheu Thai Party would make sure that police do their job in fully investigating the attack.
Deputy national police chief Pongsapat Pongcharoen said Ms Yingluck expressed grave concerns regarding the incident, branding it as press intimidation. The prime minister has ordered the national police to arrest the suspects as soon as possible.
Metropolitan Police chief Kamronwit Thoopkrachang said that the attackers might have intended to link the incident to politics in order to smear the government by implicating its supporters in the incident.
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