Export-oriented commercial farms in Mexico's Baja California state say they have offered farm workers a 15-percent wage increase to end a two-week-old strike.

But leaders of the farmworkers called the offer unacceptable, and said they want assured benefits, higher wages and an end to abuses.

The strike by an estimated 50,000 farmworkers has featured intermittent blockages of the main north-south highway in Baja, confrontations with police and the arrest of dozens of strike supporters.

The Baja California state government said that thousands of workers had returned to the berry and vegetable fields, and that production had been resumed on 85 to 90 percent of farm acreage.

But strike activist Fermin Salazar said Monday the work stoppage continued and that the 15-percent offer "was not accepted."

Workers had been demanding a 300-peso-per-day ($19.70) minimum wage, but Salazar said they have lowered that demand to 200 pesos ($13.10) per day, or piece-work pay of 20 pesos ($1.30) for each crate of strawberries they pick. At present, many farmworkers around the town of San Quintin often make less than $8 a day picking fruit and vegetables.

The San Quintin valley and surrounding areas are home to 8,500 hectares (21,000 acres) of export-oriented farms growing tomatoes, strawberries, cucumbers, onions and raspberries, among other crops.

Salazar acknowledged that many workers had returned to the fields, but said they had not given up.

"Yes, thousands of workers have returned, but they are working under protest," Salazar said. "They are waiting ... they are ready for when we make the call."

Salazar said strikers were still open to negotiating, and that strike leaders are heading to Mexicali, where they want to meet with federal, not state officials.

Baja California Gov. Francisco Vega said in a statement that workers had accepted the 15-percent raise, and said growers and strikers had reached a 64-point agreement.

But Salazar said the issues had not been resolved, and called for federal intervention.

"The state government was not able to solve the problem, that's why we need the (federal) interior secretary" to come to the Baja California state capital, Mexicali, for talks.

Marco Antonio Estudillo, a spokesman for the farm operators, said the farms would not be able to offer any more than 15 percent, saying anything higher would be commercially "unsustainable."

"An increase of this size already affects other areas of outlays, like technology and investment," Estudillo wrote in an email.

Estudillo said about 45 percent of crops had been affected by the strike as of Friday, for losses of between $80 and $100 million.

Many of the workers are migrants from southern Mexican states like Guerrero and Oaxaca who toil at huge hot-house farms just south of Ensenada. Their demands include health care, overtime pay, one paid day off per week, and an end to abuse by field bosses.

Earlier in the stoppage, hundreds of farmworkers blocked Baja's main north-south highway, burning tires and tossing rocks at vehicles. The highway blockades prompted the U.S. consulate in Tijuana to advise travelers to exercise caution.