WASHINGTON (Reuters) - The United States on Tuesday accused Bahrain of failing to protect workers' rights in its response to a March 2011 general strike at the time of the Arab Spring and asked for formal consultations under a free trade pact. "Ensuring that workers in Bahrain - and in other countries - can exercise their fundamental labor rights is a top priority for the Obama Administration," acting U.S. Trade Representative Demetrios Marantis said in a statement.

Bahraini security forces have arrested four people suspected of attacking a police checkpoint with petrol bombs south of Manama at the weekend, the interior ministry said. "Four of the terrorists who attacked police checkpoint on Sunday evening with petrol bombs have been arrested," the ministry said late Monday. It said the attack took place in the district of Jari al-Sheikh, south of the capital, adding the identity of others suspected of being involved was being probed.

US Secretary of State John Kerry pushed Bahrain Monday to step up reforms and boost human rights as he met his counterpart from the Gulf kingdom shaken by two years of Shiite-led protests. The top US diplomat spoke with Bahraini Foreign Minister Sheikh Khaled bin Ahmed al-Khalifa behind closed doors, with neither making a public statement after the talks. "Human rights were part of the discussion, and specifically, in terms of urging them to make additional progress," acting deputy State Department spokesman Patrick Ventrell told journalists.

By Yara Bayoumy DUBAI (Reuters) - The U.N. torture investigator said Bahrain had effectively cancelled a trip he had planned to the Gulf Arab state, where unrest led by majority Shi'ites against the Sunni ruling family has simmered for over two years. Juan Mendez, the U.N. Special Rapporteur on Torture, said in a statement it was the second time a scheduled visit had been postponed at short notice. His trip had been set for May 8-15.