Kuwaiti customs officers pressed a strike into a second day on Tuesday, severely disrupting air, sea and land trade and threatening to halt oil exports, a trade union official said.
"The strike is still on and we will continue until our demands are fully met," Fahhad al-Ajmi, board member of the customs trade union, told AFP.
More than 3,000 customs employees went on strike Monday demanding a pay raise and improved working conditions.
Ajmi said that movement at Kuwait's border exit points, including three commercial seaports and the only international airport, were "severely affected" and only humanitarian cases were allowed.
As many as 1,000 trucks loaded with fruits, vegetables and other goods "remained stranded at the border posts," Ajmi said, adding that only passenger vehicles were inspected by customs officers.
The oil-rich desert state, OPEC's third largest producer, depends almost entirely on imports to meet consumption needs, especially in the fresh produce sector.
Ajmi insisted that "oil exports will be hit severely within the coming few days and could lead to a halt in production" if the strike is not resolved.
The oil ministry and the Kuwait Petroleum Corp. (KPC) have yet to comment on the strike, but an industry source told AFP that oil exports have not been affected.
Ajmi however claimed that about six to seven oil tankers have been barred from sailing out of Kuwait since Monday because customs officers refused to give them the necessary clearance to leave.
Al-Watan newspaper on Tuesday cited the head of the Customs Department, Ibrahim al-Ghanem, appealing to customs officers not to disrupt oil shipments.
Ghanem on Monday called on workers to end their strike with a promise from Finance Minister Mustafa al-Shamali, to meet their demands but the employees refused.
Ajmi said that fresh appeals were made by the minister Monday night but the workers again rejected his offer.
"We will not end our strike until the government issues a clear statement accepting our demands in full," Ajmi said.
Kuwait has been hit by a spate of industrial action in the public sector, which employs close to 80 percent of the 360,000-strong workforce of Kuwaiti nationals.
The country has about 1.7 million foreign workers, mostly employed by the private sector.
The Gulf state, with 1.2 million Kuwaiti citizens, offers a cradle-to-grave welfare system with public services and fuel offered either free or at heavily subsidised prices, and no taxes.