KUALA LUMPUR, March 7 — North Korea barred Malaysians from leaving the country today, sparking tit-for-tat action by Malaysia, as police investigating the murder of Kim Jong-nam in Kuala Lumpur sought to question three men hiding in the North Korean embassy.

Following is a chronology of ties between the two countries.

1973 — Malaysia and North Korea establish diplomatic ties.

1995 — Malaysia hosts talks between the United States and North Korea over freezing North Korea’s nuclear programme.

2009 — Malaysia becomes first country whose citizens are allowed to travel to North Korea without a visa. North Koreans get the same privilege.

2011 — North Korea’s state airline, Air Koryo, opens a route to Malaysia to attract more tourists.

2013 — Malaysia’s HELP university confers an honorary doctorate degree on North Korea Leader Kim Jong-un.

Feb 13 — North Korean leader Kim Jong-un’s half-brother, Kim Jong-nam, is murdered at Kuala Lumpur International Airport.

Feb 15 — US government believes North Korean agents were behind the murder, US government source says.

Feb 15 — China had been protecting Kim Jong-nam, according to South Korea’s spy agency.

Feb 15 — North Korea’s leader had “standing order” to kill Kim Jong-nam, South Korean lawmaker says quoting Seoul’s intelligence agency.

Feb 16 — Malaysian police arrest Vietnamese and Indonesian women in murder case.

Feb 19 — Malaysian police say four North Korean suspects left the country the same day of the murder.

Feb 20 — North Korean ambassador says Malaysia trying to delay release of victim’s body for “political aim”, says police investigation cannot be trusted.

Feb 22 — Malaysia identifies North Korean embassy official, employee of state airline among suspects.

Feb 22- Malaysia says no family members of Kim Jong-nam have come forward to identify body or give DNA samples.

Feb 23 — North Korea blames Malaysia, South Korea for death of one of its citizens.

Feb 24 — Police say VX nerve agent, a chemical the UN classifies as a weapon of mass destruction, was used to assassinate Kim Jong-nam.

Feb 26 — Malaysia declares Kuala Lumpur International Airport a “safe zone” after completing decontamination sweep.

Feb 27 — South Korean lawmaker says airport assassins were from North Korea’s ministry of state security and the foreign ministry.

March 1 — Malaysia charges Indonesian and Vietnamese with Kim Jong-nam’s murder.

March 2 — North Korea says heart attack likely killed airport victim.

March 4 — Malaysia rejects suggestions it may have violated UN sanctions after a Reuters report said North Korea-linked firms were running an arms network in the country.

March 4 — Malaysia deports North Korean suspect in Kim Jong-nam’s murder, saying it had insufficient evidence to charge him.

March 6 — Malaysia cancels visa waiver programme.

March 6 — Malaysia expels North Korean ambassador Kang Chol.

March 6 — Malaysia asks that an Asian Cup football qualifier against North Korea be moved from Pyongyang to a neutral venue. — Reuters