Bangkok - A bomb hurled Thursday morning at protestors at Klong Toey Market in Bangkok injured 13 people, two of whom were in critical condition, police said.

"Eyewitnesses said the bomb was thrown by a man on a motorcycle from the bridge that overlooks the market," said Police Colonel Suthip Palitkusontat, of the Klong Toey Port Police Station.

Vendors at the famed open air market - the largest in the capital - have been protesting efforts to evict them by a private company that won a new lease on the area on October 29.

The market is owned by the Port Authority of Thailand (PAT), the state enterprise that operates Bangkok's Klong Toey Port and other commercial ports in the kingdom.

In March, the PAT ended its concession with the previous operator of Klong Toey market, and took new bids from the private sector.

Legal Professional Company was granted the concession on October 29, but the old operator, comprising three companies, has refused to vacate the market and continues to collect rents from more than 1,000 vendors, PAT officials said.

The chairman of Legal Professional is Thamanat Pompao, whom Klong Toey vendors claim is a former army captain with a criminal record.

The vendors, worried that Legal Professional will increase their rents, have been protesting against the new management since Tuesday, disrupting traffic in the area.

The protest was stopped temporarily on Thursday, in a show of deference to the royal funeral for Princess Galyani Vadhana, King Bhumibol Adulyadej's eldest sister who died in January.

Protests are set to resume after the funeral ends on Tuesday. (dpa)