Ukrainian lawmakers on Tuesday adopted legislation granting limited self-rule to parts of the pro-Russian east as they prepared to ratify a landmark EU pact at the heart of the country's deadliest crisis since independence.

From Washington and Paris to Tehran and Damascus, it seems everyone agrees on the growing need to fight "terrorism". What exactly the word means is another matter entirely.

In what was once the Ukrainian secret service headquarters in Donetsk, a group of women, eyes rimmed in red, come seeking the help of the city's new rebel masters in an anguished search for missing husbands and sons.

International observers with the OSCE came under fire in restive eastern Ukraine on Sunday in what the mission described as an "unacceptable" incident.

The six monitors were unharmed despite their vehicles being hit by mortar or artillery fire in the rebel-held Donetsk area as fighting flared between Ukrainian forces and pro-Russian rebels. The incident was one of many undermining a shaky ceasefire in place since September 5.

A proposed sale of Israeli weapons including drones to Ukraine has been blocked for fear of antagonizing Russia, Channel Two television reported on Monday.

The broadcaster said a Ukrainian delegation had visited Israel with a view to acquiring military hardware including drones to use against pro-Russian separatists.

The United States on Monday rejected as illegitimate the first local elections in Crimea since Russia annexed the peninsula from Ukraine in March.

"The United States does not recognize the legitimacy of the so-called local and regional elections in Crimea on September 14 and will not acknowledge their outcome," State Department deputy spokeswoman Marie Harf told reporters.

Ukraine's president on Monday offered parts of the ex-Soviet country's separatist east limited self-rule for three years under the terms of a peace plan reached with Russia.

Petro Poroshenko's official website said the pro-Western leader told top lawmakers the proposal would be part of a broader deal with pro-Russian rebels signed on September 5.

Ukrainian President Petro Poroshenko faces a strong backlash from some of his staunchest supporters for bowing to Russian pressure and postponing the implementation of an EU trade pact which is due to be ratified Tuesday.

Several of them have warned the decision to delay the ex-Soviet state's economic tilt westward could spark a repeat of the EuroMaidan protests that toppled Kremlin-backed Viktor Yanukovych earlier this year, after he rejected the same deal.

Bosnian Serbs are closely watching Scotland's independence referendum, hoping if Scots vote to break away from Britain it would set a precedent that could boost their own chances of proclaiming a separate state.

The French, German and Russian foreign ministers on Monday held closed-door talks in Paris over the Ukraine crisis, a German foreign ministry official said.

There were however no details of the discussions between France's Laurent Fabius, Germany's Frank-Walter Steinmeier and Sergei Lavrov of Russia after a giant international conference on fighting Islamic State militants in Iraq.